Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
Stein - Use Google Sheets as your no-setup database
FriendlyData - Communicate with databases like a human
Tabletop.js - Easily use Google Spreadsheets in JavaScript
SpreadsheetDB - A database that you can query with spreadsheets
CalcFusion - CalcFusion enables users to transform Spreadsheets into APIs that can be plugged into any IT system.