Example App

Let's imagine the following code is placed in garrysmod/addons/myfirstapp/lua/gpapps/testapp.lua. The GPhone will automatically add it to the App-list once the map loads.

You can also place it in garrysmod/data/gphone/apps/testapp.txt, though you'll have to enable the ConVar gphone_csapp and other players won't be able to use it.

APP.Name        = "TestApp"                       -- The name of the App
APP.Author      = "TesterChester"                 -- The author's name
APP.Negative    = false                           -- Whether the App should use negative top-colors or not
APP.Icon        = "https://example.com/icon.png"  -- The icon. Can point to a local file or an online file
function APP.Run( frame, w, h, ratio )            -- Called when the App is first opened (frame, width, height, aspect ratio)
    function frame:Paint( x, y, w, h )
        draw.RoundedBox( 0, 0, 0, w, h, Color( 200, 200, 200, 255 ) )
    end
    
    local button = GPnl.AddPanel( frame, "panel" ) -- Creates a panel of type "panel"
    button:SetPos( 32*ratio, 32*ratio )            -- By multiplying with "ratio" we can support all resolutions
    button:SetSize( w - 64*ratio, 64*ratio )
    button.Color = Color( 0, 255, 0 ) -- Green color
    function button:Paint( x, y, w, h )
        draw.RoundedBox( 0, 0, 0, w, h, self.Color ) -- Paint the button using the color
    end
    function button:OnClick() -- Called when we click
        self.Color = Color( 255, 0, 0 ) -- Red color
    end
end
function APP.Think( frame, w, h, ratio ) -- Called every time the SWEP.Think function is called
    print("thonk")
end
function APP.Stop( frame ) -- Called when the App is closed
    print("closed")
end

hook.Add("GPhonePreRenderTopbar", "TopbarBackgroundTest", function(w, h) -- Draw a green background behind the Topbar
    surface.SetDrawColor(0, 255, 0, 255)
    surface.DrawRect(0, 0, w, h)
end)

This App obviously doesn't do that much, but you could practially do anything GLua allows if you are willing to put in the work.