Automate the sharing of a google drive folder via form submission
Create a google form that includes at a minimum a question for a gmail (or google apps) email address.
Go into the spreadsheet where responses are stored, click tools, then click script editor.
Select create script for blank project and paste in the code from share.js.
Edit the variables at the top of the script to indicate which column the gmail addresses are stored in, which column the script should write to to indicate sharing status, and the ID of the folder to be shared. (ID can be found in the URL when opening the folder in drive.google.com)
Under resources select "Current Project's Triggers", name your project, and add a new trigger for the addNewUsers function so the script is run upon a new form submission.