DBeaver - DBeaver - Universal Database Manager and SQL Client.
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
SQuirreL SQL - SQuirreL SQL is an open-source Java SQL Client program for any JDBC compliant database
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
DBComparer - Free Compare database tool - DBComparer 3.0 is a professional compare database tool for comparing Microsoft SQL Server 2008 (and 2005) database structure.
Sheetsu - Turn Google Spreadsheet into API