SpreadSimple - A blazing-fast way to create and manage sites using Google Spreadsheets
Launchcloud - Data collection & automation made simple.
Algo by AirDev - Turn a Google Sheet model into a web app in 5 minutes
Forms Manager - Forms Manager is an online form of automation software that helps businesses build forms, manage workflows, and analyze real-time reports.
Sheety - Turn any Google sheet into an API instantly, for free. Power websites, apps, or whatever you like, all from a spreadsheet. Changes to your spreadsheet update your API in realtime. Neat
XForms - Forms automation solution for medium to large firms