Sheetsu - Turn Google Spreadsheet into API
PencilCase - Transform your designs into native iOS apps in a heartbeat.
SpreadSimple - A blazing-fast way to create and manage sites using Google Spreadsheets
Creo - Creo is a modern design tool for Mac which combines design and development.
SheetAside - Access your Google Sheets from where you are
Rainbow Pencils - Make rainbows whenever you sharpen.