I wrote a small script bound to a Google spreadsheet that reads an email-address from a cell in the last row and sends an email to it. The values are collected by a WebApp (not by Google form).
I tried all kind of triggers. The time driven triggers work, but the spreadsheet triggers don't work. I tried all of them. If I change manually some cell in the spreadsheet the onEdit trigger is working, but it doesn't fire up when the sheet was changed by another script.