The Ultimate Google Sheet Toolkit - We put together a curated list of templates, videos, and tutorials that can help you build your analytics expertise.
Sheetsu - Turn Google Spreadsheet into API
Google Sheets + MonkeyLearn - Power up your Google Sheets with text analysis
SpreadSimple - A blazing-fast way to create and manage sites using Google Spreadsheets
SheetHacks by Polymer Search - Discover the best tips & tricks for Google Sheets & Excel
SheetAside - Access your Google Sheets from where you are