diff --git a/sponsoredTransactionsAuction/frontend/src/auction_contract.tsx b/sponsoredTransactionsAuction/frontend/src/auction_contract.tsx
index 6e5610a5..aacad357 100644
--- a/sponsoredTransactionsAuction/frontend/src/auction_contract.tsx
+++ b/sponsoredTransactionsAuction/frontend/src/auction_contract.tsx
@@ -1,4 +1,4 @@
-import * as AuctionContract from '../generated/sponsored_tx_enabled_auction_sponsored_tx_enabled_auction'; // Code generated from a smart contract module.
+import * as AuctionContract from '../generated/sponsored_tx_enabled_auction_sponsored_tx_enabled_auction'; // Code generated from a smart contract module. The naming convention of the generated file is `moduleName_smartContractName`.
 
 import {
     AccountTransactionType,
@@ -34,14 +34,15 @@ const contract = AuctionContract.createUnchecked(
     ContractAddress.create(Number(process.env.AUCTION_CONTRACT_INDEX), CONTRACT_SUB_INDEX),
 );
 
-// This function submits a transaction to add an item to the auction contract.
+export const AUCTION_CONTRACT = contract;
+
 /**
- * Add new item to the auction contract.
+ * This function submits a transaction to add an item to the auction contract.
  *
- * @param connection - The wallet connection to use for sending the transaction
- * @param accountAddress - The account address to send from
- * @param addItemParameter - The parameter for the add item function
- * @throws If the contract could not be updated
+ * @param connection - The wallet connection to use for sending the transaction.
+ * @param accountAddress - The account address to send from.
+ * @param addItemParameter - The parameter for the addItem function.
+ * @throws If simulating the contract update fails.
  * @returns A promise resolving with the corresponding {@linkcode TransactionHash.Type}
  */
 export async function addItem(
@@ -63,11 +64,11 @@ export async function addItem(
         );
     }
 
-    const maxContractExecutionEnergy = Energy.create(dryRunResult.usedEnergy.value + EPSILON_ENERGY); // + EPSILON_ENERGY needs to be here, as there seems to be an issue with running out of energy 1 energy prior to reaching the execution limit
+    const maxContractExecutionEnergy = Energy.create(dryRunResult.usedEnergy.value + EPSILON_ENERGY);
 
     const payload: Omit<UpdateContractPayload, 'message'> = {
         amount: CcdAmount.zero(),
-        address: ContractAddress.create(Number(process.env.AUCTION_CONTRACT_INDEX), CONTRACT_SUB_INDEX),
+        address: contract.contractAddress,
         receiveName: ReceiveName.create(AuctionContract.contractName, EntrypointName.fromString('addItem')),
         maxContractExecutionEnergy,
     };
@@ -94,13 +95,11 @@ export async function addItem(
 }
 
 /**
- * TODO: update comment
- * View item state.
- * @param connection - The wallet connection to use for sending the transaction
- * @param accountAddress - The account address to send from
- * @param mintParameter - The parameter for the mint function
- * @throws If the contract could not be updated
- * @returns A promise resolving with the corresponding {@linkcode TransactionHash.Type}
+ * This function views the item state in the auction contract.
+ *
+ * @param viewItemState - The parameter for the viewItemState function.
+ * @throws If the communicate with the Concordium node fails, the smart contract reverts, or parsing the returnValue fails.
+ * @returns A promise resolving with the corresponding {@linkcode AuctionContract.ReturnValueViewItemState}
  */
 export async function viewItemState(
     viewItemState: AuctionContract.ViewItemStateParameter,
diff --git a/sponsoredTransactionsAuction/frontend/src/cis2_token_contract.tsx b/sponsoredTransactionsAuction/frontend/src/cis2_token_contract.tsx
index a19977a6..1c2e1401 100644
--- a/sponsoredTransactionsAuction/frontend/src/cis2_token_contract.tsx
+++ b/sponsoredTransactionsAuction/frontend/src/cis2_token_contract.tsx
@@ -1,4 +1,4 @@
-import * as Cis2MultiContract from '../generated/cis2_multi_cis2_multi'; // Code generated from a smart contract module.
+import * as Cis2MultiContract from '../generated/cis2_multi_cis2_multi'; // Code generated from a smart contract module. The naming convention of the generated file is `moduleName_smartContractName`.
 
 import {
     AccountTransactionType,
@@ -33,14 +33,15 @@ const contract = Cis2MultiContract.createUnchecked(
     ContractAddress.create(Number(process.env.CIS2_TOKEN_CONTRACT_INDEX), CONTRACT_SUB_INDEX),
 );
 
-// This function submits a transaction to mint/airdrop tokens to an account.
+export const CIS2_TOKEN_CONTRACT = contract;
+
 /**
- * Mints new cis2 tokens to the account specified in the mintParameter.
+ * This function submits a transaction to mint/airdrop cis2_multi tokens to an account.
  *
- * @param connection - The wallet connection to use for sending the transaction
- * @param accountAddress - The account address to send from
- * @param mintParameter - The parameter for the mint function
- * @throws If the contract could not be updated
+ * @param connection - The wallet connection to use for sending the transaction.
+ * @param accountAddress - The account address to send from.
+ * @param mintParameter - The parameter for the mint function.
+ * @throws If simulating the contract update fails or the `mintParameter.owner` is not an account.
  * @returns A promise resolving with the corresponding {@linkcode TransactionHash.Type}
  */
 export async function mint(
@@ -62,11 +63,11 @@ export async function mint(
         );
     }
 
-    const maxContractExecutionEnergy = Energy.create(dryRunResult.usedEnergy.value + EPSILON_ENERGY); // + EPSILON_ENERGY needs to be here, as there seems to be an issue with running out of energy 1 energy prior to reaching the execution limit
+    const maxContractExecutionEnergy = Energy.create(dryRunResult.usedEnergy.value + EPSILON_ENERGY);
 
     const payload: Omit<UpdateContractPayload, 'message'> = {
         amount: CcdAmount.zero(),
-        address: ContractAddress.create(Number(process.env.CIS2_TOKEN_CONTRACT_INDEX), CONTRACT_SUB_INDEX),
+        address: contract.contractAddress,
         receiveName: ReceiveName.create(Cis2MultiContract.contractName, EntrypointName.fromString('mint')),
         maxContractExecutionEnergy,
     };
@@ -105,13 +106,11 @@ export async function mint(
 }
 
 /**
- * Mints new cis2 tokens to the account specified in the mintParameter.
+ * This function views the nonce (CIS3 standard) of an acccount in the cis2_multi contract.
  *
- * @param connection - The wallet connection to use for sending the transaction
- * @param accountAddress - The account address to send from
- * @param mintParameter - The parameter for the mint function
- * @throws If the contract could not be updated
- * @returns A promise resolving with the corresponding {@linkcode TransactionHash.Type}
+ * @param nonceOfParameter - The parameter for the nonceOf function.
+ * @throws If the communicate with the Concordium node fails, the smart contract reverts, or parsing the returnValue fails.
+ * @returns A promise resolving with the corresponding {@linkcode Cis2MultiContract.ReturnValueNonceOf}
  */
 export async function nonceOf(
     nonceOfParameter: Cis2MultiContract.NonceOfParameter,
diff --git a/sponsoredTransactionsAuction/frontend/src/components/AddItemToAuction.tsx b/sponsoredTransactionsAuction/frontend/src/components/AddItemToAuction.tsx
index f2eeaf78..b0512a3c 100644
--- a/sponsoredTransactionsAuction/frontend/src/components/AddItemToAuction.tsx
+++ b/sponsoredTransactionsAuction/frontend/src/components/AddItemToAuction.tsx
@@ -14,8 +14,8 @@ import {
 } from '@concordium/web-sdk';
 
 import { AUCTION_END, AUCTION_START } from '../constants';
-import { addItem } from '../auction_contract';
 
+import { addItem } from '../auction_contract';
 import * as AuctionContract from '../../generated/sponsored_tx_enabled_auction_sponsored_tx_enabled_auction'; // Code generated from a smart contract module.
 
 interface ConnectionProps {
@@ -88,7 +88,7 @@ export default function AddItemToAuction(props: ConnectionProps) {
 
                         setItemIndex(parsedEvent.content.item_index);
                     } else {
-                        setItemIndexError('Tansaction failed or event decoding failed.');
+                        setItemIndexError('Tansaction failed and event decoding failed.');
                     }
                 })
                 .catch((e) => {
diff --git a/sponsoredTransactionsAuction/frontend/src/components/App/App.tsx b/sponsoredTransactionsAuction/frontend/src/components/App/App.tsx
index 36fb1640..389fec39 100644
--- a/sponsoredTransactionsAuction/frontend/src/components/App/App.tsx
+++ b/sponsoredTransactionsAuction/frontend/src/components/App/App.tsx
@@ -21,9 +21,9 @@ import Footer from '../Footer';
 import { BROWSER_WALLET, REFRESH_INTERVAL } from '../../constants';
 
 import { nonceOf } from '../../cis2_token_contract';
-import * as Cis2MultiContract from '../../../generated/cis2_multi_cis2_multi'; // Code generated from a smart contract module.
+import * as Cis2MultiContract from '../../../generated/cis2_multi_cis2_multi';
 
-/*
+/**
  * The main component that manages the wallet connection.
  * It imports and displays the four components `MintTokens`, `AddItemToAuction`, `ViewItem`, and `Bid`.
  */
@@ -47,6 +47,9 @@ export default function App(props: WalletConnectionProps) {
     const [txHash, setTxHash] = useState<undefined | TransactionHash.Type>(undefined);
     const [transactionError, setTransactionError] = useState<string | undefined>(undefined);
 
+    /**
+     * This function querries the nonce (CIS3 standard) of an acccount in the cis2_multi contract.
+     */
     const refreshNonce = useCallback(() => {
         if (grpcClient && account) {
             const nonceOfParam: Cis2MultiContract.NonceOfParameter = [AccountAddress.fromBase58(account)];
@@ -72,9 +75,10 @@ export default function App(props: WalletConnectionProps) {
         return () => clearInterval(interval);
     }, [refreshNonce]);
 
-    /*
-     * This function gets the public key of an account.
-     * This function works with a wallet account that has just one public-private key pair in its two-level key map.
+    /**
+     * This function gets the public key of an account. The function can be used
+     * for accounts generated in the browser and mobile wallets
+     * that have just one public-private key pair in their two-level key map.
      */
     const getPublicKey = useCallback(
         (account: string | undefined) => {
diff --git a/sponsoredTransactionsAuction/frontend/src/components/Bid.tsx b/sponsoredTransactionsAuction/frontend/src/components/Bid.tsx
index 05db91b7..29ea3bd0 100644
--- a/sponsoredTransactionsAuction/frontend/src/components/Bid.tsx
+++ b/sponsoredTransactionsAuction/frontend/src/components/Bid.tsx
@@ -11,15 +11,14 @@ import {
     SERIALIZATION_HELPER_SCHEMA_ADDITIONAL_DATA,
     SERIALIZATION_HELPER_SCHEMA_PERMIT_MESSAGE,
     TRANSFER_SCHEMA,
-    VERIFIER_URL,
 } from '../constants';
-
 import { submitBid, validateAccountAddress } from '../utils';
-import { viewItemState } from '../auction_contract';
 
+import { AUCTION_CONTRACT, viewItemState } from '../auction_contract';
+import { CIS2_TOKEN_CONTRACT } from '../cis2_token_contract';
 import * as AuctionContract from '../../generated/sponsored_tx_enabled_auction_sponsored_tx_enabled_auction'; // Code generated from a smart contract module.
 
-/*
+/**
  * This function generates the transfer message to be signed in the browser wallet.
  */
 async function generateTransferMessage(
@@ -37,6 +36,7 @@ async function generateTransferMessage(
             throw new Error(`ItemIndex is NaN.`);
         }
 
+        // Figure out the `tokenId` that the item is up for auction.
         const itemState: AuctionContract.ReturnValueViewItemState = await viewItemState(viewItemStateParam);
 
         setTokenID(itemState.token_id);
@@ -48,21 +48,18 @@ async function generateTransferMessage(
 
         const hexStringData = [...data.buffer].map((b) => b.toString(16).padStart(2, '0')).join('');
 
+        // Generate transfer parameter.
         const transfer = [
             {
                 amount,
-                data: hexStringData, // e.g. 0100 (for item with index 1)
+                // The item index in the auction contract is of type u16. 
+                // A little endian hex string of 2 bytes represents the index here. E.g. `0100` for item with index 1.
+                data: hexStringData,
                 from: {
                     Account: [account],
                 },
                 to: {
-                    Contract: [
-                        {
-                            index: Number(process.env.AUCTION_CONTRACT_INDEX),
-                            subindex: 0,
-                        },
-                        'bid',
-                    ],
+                    Contract: [AUCTION_CONTRACT.contractAddress, 'bid'],
                 },
                 token_id: itemState.token_id,
             },
@@ -71,10 +68,7 @@ async function generateTransferMessage(
         const payload = serializeTypeValue(transfer, toBuffer(TRANSFER_SCHEMA, 'base64'));
 
         const message = {
-            contract_address: {
-                index: Number(process.env.CIS2_TOKEN_CONTRACT_INDEX),
-                subindex: 0,
-            },
+            contract_address: CIS2_TOKEN_CONTRACT.contractAddress,
             nonce: Number(nonce),
             timestamp: expiryTimeSignature,
             entry_point: 'transfer',
@@ -99,7 +93,7 @@ interface ConnectionProps {
     setTransactionError: (error: string | undefined) => void;
 }
 
-/*
+/**
  * A component that manages the input fields and corresponding state to sign a bid message and submit the signature to the backend.
  */
 export default function Bid(props: ConnectionProps) {
@@ -129,6 +123,9 @@ export default function Bid(props: ConnectionProps) {
     }
     const formBid = useForm<FormTypeBid>({ mode: 'all' });
 
+    /**
+     * When submitting the form, the browser wallet is prompt to sign the transferMessage.
+     */
     async function onSubmitSigning(data: FormTypeGenerateSignature) {
         setSigningError(undefined);
         setSignature(undefined);
@@ -165,6 +162,9 @@ export default function Bid(props: ConnectionProps) {
         }
     }
 
+    /**
+     * When submitting the form, the generated signature from the previous step is sent to the backend.
+     */
     function onSubmitBid(data: FormTypeBid, accountAddress: string | undefined) {
         setTxHash(undefined);
         setTransactionError(undefined);
@@ -172,7 +172,6 @@ export default function Bid(props: ConnectionProps) {
 
         if (accountAddress && signature) {
             const tx = submitBid(
-                VERIFIER_URL,
                 data.signer,
                 nonce,
                 signature,
diff --git a/sponsoredTransactionsAuction/frontend/src/components/CCDScanLinks.tsx b/sponsoredTransactionsAuction/frontend/src/components/CCDScanLinks.tsx
index c8e0daab..e8147c27 100644
--- a/sponsoredTransactionsAuction/frontend/src/components/CCDScanLinks.tsx
+++ b/sponsoredTransactionsAuction/frontend/src/components/CCDScanLinks.tsx
@@ -4,7 +4,7 @@ interface TxHashLinkProps {
     txHash: TransactionHash.Type;
 }
 
-/*
+/**
  * A component that displays the CCDScan link of a transaction hash.
  */
 export const TxHashLink = function TxHashLink(props: TxHashLinkProps) {
@@ -30,7 +30,7 @@ interface AccountLinkProps {
     account: string;
 }
 
-/*
+/**
  * A component that displays the CCDScan link to an account address.
  */
 export const AccountLink = function AccountLink(props: AccountLinkProps) {
diff --git a/sponsoredTransactionsAuction/frontend/src/components/Footer.tsx b/sponsoredTransactionsAuction/frontend/src/components/Footer.tsx
index 11866a15..da152ab9 100644
--- a/sponsoredTransactionsAuction/frontend/src/components/Footer.tsx
+++ b/sponsoredTransactionsAuction/frontend/src/components/Footer.tsx
@@ -1,6 +1,6 @@
 import { version } from '../../package.json';
 
-/*
+/**
  * A component that displays a link to the developer documentation and the version of the app.
  */
 export default function Footer() {
diff --git a/sponsoredTransactionsAuction/frontend/src/components/MintTokens.tsx b/sponsoredTransactionsAuction/frontend/src/components/MintTokens.tsx
index 135e9dd3..ab2b92b2 100644
--- a/sponsoredTransactionsAuction/frontend/src/components/MintTokens.tsx
+++ b/sponsoredTransactionsAuction/frontend/src/components/MintTokens.tsx
@@ -3,13 +3,13 @@ import { useForm } from 'react-hook-form';
 import { Alert, Button, Form } from 'react-bootstrap';
 
 import { WalletConnection } from '@concordium/react-components';
-import { mint } from '../cis2_token_contract';
 import { AccountAddress, TransactionHash } from '@concordium/web-sdk';
 
 import { METADATA_URL } from '../constants';
+import { validateAccountAddress } from '../utils';
 
+import { mint } from '../cis2_token_contract';
 import * as Cis2MultiContract from '../../generated/cis2_multi_cis2_multi'; // Code generated from a smart contract module.
-import { validateAccountAddress } from '../utils';
 
 interface ConnectionProps {
     setTxHash: (hash: TransactionHash.Type | undefined) => void;
@@ -18,7 +18,7 @@ interface ConnectionProps {
     connection: WalletConnection;
 }
 
-/*
+/**
  * A component that manages the input fields and corresponding state to mint/airdrop some cis2 tokens to the user.
  * This component creates an `Update` transaction.
  */
@@ -48,6 +48,9 @@ export default function MintTokens(props: ConnectionProps) {
                     hash: { type: 'None' },
                     url: METADATA_URL, // In production, you should consider using a different metadata file for each token_id.
                 },
+                // The token id in the cis2 token contract is of type u8. 
+                // A hex string of 1 byte represents the token id here. E.g. `01` for token id 1. 
+                // The input field has a max/min value validation, so that `data.tokenID` is not greater than 255.
                 token_id: `0${Number(data.tokenID).toString(16)}`.slice(-2),
             };
 
diff --git a/sponsoredTransactionsAuction/frontend/src/components/ViewItem.tsx b/sponsoredTransactionsAuction/frontend/src/components/ViewItem.tsx
index 03818270..f5932157 100644
--- a/sponsoredTransactionsAuction/frontend/src/components/ViewItem.tsx
+++ b/sponsoredTransactionsAuction/frontend/src/components/ViewItem.tsx
@@ -13,7 +13,7 @@ interface ConnectionProps {
     grpcClient: ConcordiumGRPCClient | undefined;
 }
 
-/*
+/**
  * A component that manages the input fields and corresponding state to view an item in the auction contract.
  */
 export default function ViewItem(props: ConnectionProps) {
diff --git a/sponsoredTransactionsAuction/frontend/src/constants.ts b/sponsoredTransactionsAuction/frontend/src/constants.ts
index a2a1b6c2..b9922fdf 100644
--- a/sponsoredTransactionsAuction/frontend/src/constants.ts
+++ b/sponsoredTransactionsAuction/frontend/src/constants.ts
@@ -16,6 +16,11 @@ export const AUCTION_CONTRACT_NAME = ContractName.fromString('sponsored_tx_enabl
 
 export const CONTRACT_SUB_INDEX = 0n;
 
+// Before submitting a transaction we simulate/dry-run the transaction to get an
+// estimate of the energy needed for executing the transaction. In addition, we
+// allow an additional small amount of energy `EPSILON_ENERGY` to be consumed by
+// the transaction to cover small variations (e.g. changes to the smart contract
+// state) caused by transactions that have been executed meanwhile.
 export const EPSILON_ENERGY = 1000n;
 
 export const AUCTION_START = '2000-01-01T12:00:00Z'; // Hardcoded value for simplicity for this demo dApp.
diff --git a/sponsoredTransactionsAuction/frontend/src/scss/_components.scss b/sponsoredTransactionsAuction/frontend/src/scss/_components.scss
deleted file mode 100644
index abeeb5aa..00000000
--- a/sponsoredTransactionsAuction/frontend/src/scss/_components.scss
+++ /dev/null
@@ -1,2 +0,0 @@
-// Project components
-// @import 'components/App';
diff --git a/sponsoredTransactionsAuction/frontend/src/scss/index.scss b/sponsoredTransactionsAuction/frontend/src/scss/index.scss
index 8c4e8ef9..87071ece 100644
--- a/sponsoredTransactionsAuction/frontend/src/scss/index.scss
+++ b/sponsoredTransactionsAuction/frontend/src/scss/index.scss
@@ -1,4 +1,3 @@
 @import 'config';
 @import 'bootstrap-config';
 @import 'layout';
-@import 'components';
diff --git a/sponsoredTransactionsAuction/frontend/src/scss/layout/_accordion.scss b/sponsoredTransactionsAuction/frontend/src/scss/layout/_accordion.scss
deleted file mode 100644
index 367d6b04..00000000
--- a/sponsoredTransactionsAuction/frontend/src/scss/layout/_accordion.scss
+++ /dev/null
@@ -1,8 +0,0 @@
-@import 'bootstrap/scss/accordion';
-
-.accordion-button {
-    &:not(.collapsed) {
-        color: $ocean-blue;
-        background: $header-gradient;
-    }
-}
diff --git a/sponsoredTransactionsAuction/frontend/src/scss/layout/_modal.scss b/sponsoredTransactionsAuction/frontend/src/scss/layout/_modal.scss
deleted file mode 100644
index ad29c899..00000000
--- a/sponsoredTransactionsAuction/frontend/src/scss/layout/_modal.scss
+++ /dev/null
@@ -1,6 +0,0 @@
-@import 'bootstrap/scss/modal';
-
-.modal-header {
-    color: $ocean-blue;
-    background: $header-gradient;
-}
diff --git a/sponsoredTransactionsAuction/frontend/src/utils.ts b/sponsoredTransactionsAuction/frontend/src/utils.ts
index 6d333018..78563e5f 100644
--- a/sponsoredTransactionsAuction/frontend/src/utils.ts
+++ b/sponsoredTransactionsAuction/frontend/src/utils.ts
@@ -1,11 +1,25 @@
 import { AccountAddress, TransactionHash } from '@concordium/web-sdk';
 
-/*
+import {
+    VERIFIER_URL,
+} from './constants';
+
+/**
  * This function sends the bidding signature and other parameters to the back end.
  * The back end will send the sponsored transaction on behalf of the user to the chain.
+ *
+ * @param signer - The account that signed the transferMessage.
+ * @param nonce - The nonce (CIS3 standard) that was part of the message that was signed. 
+ * @param signature - The signature that was generated by the wallet.
+ * @param expiryTimeSignature - The timestamp when the signature expires.
+ * @param tokenID - The tokenID that was part of the message that was signed.
+ * @param from - The from address that was part of the message that was signed.
+ * @param tokenAmount - The tokenAmount that was part of the message that was signed.
+ * @param itemIndexAuction - The itemIndexAuction that was part of the message that was signed.
+ * @throws If the server responds with an error or the response of the server is malformed.
+ * @returns The {@linkcode TransactionHash.Type} of the transaction submitted at the backend.
  */
 export async function submitBid(
-    backend: string,
     signer: string,
     nonce: string,
     signature: string,
@@ -15,7 +29,7 @@ export async function submitBid(
     tokenAmount: string | undefined,
     itemIndexAuction: string | undefined,
 ) {
-    const response = await fetch(`${backend}/bid`, {
+    const response = await fetch(`${VERIFIER_URL}/bid`, {
         method: 'POST',
         headers: new Headers({ 'content-type': 'application/json' }),
         body: JSON.stringify({
@@ -41,12 +55,18 @@ export async function submitBid(
     throw new Error('Unable to submit bid');
 }
 
+/**
+ * This function validates if a string represents a valid accountAddress in base58 encoding. 
+ * The length, characters, and the checksum are validated.
+ *
+ * @param accountAddress - An account address represented as a base58 encoded string.
+ * @returns An error message if validation fails.
+ */
 export function validateAccountAddress(accountAddress: string) {
     try {
         AccountAddress.fromBase58(accountAddress);
     } catch (e) {
-        return `Please enter a valid account address. It is a base58 string with a fixed length of 50 characters. Original error: ${
-            (e as Error).message
-        }.`;
+        return `Please enter a valid account address. It is a base58 string with a fixed length of 50 characters. Original error: ${(e as Error).message
+            }.`;
     }
 }