Tabulate

Tabulate is a user-friendly web interface to MySQL databases. For more information, please read the docs.

Install

Run the backup script: ./tabulate backup /path/to/backup/directory/ (will create a single file named e.g. tabulate_site_name_here_2015-01-01.tgz)
Copy the backup file to somewhere safe.

Tables can be filtered by any column or columns, and with a range of operators ('contains', 'is', 'empty', 'one of', 'greater than', 'less than', and the negations of all of these). Multiple filters are conjunctive (i.e. with a logical and).
Access can be granted to read, create, update, delete, and import records in any or all tables. (This can be done by anyone with the promote_users capability.) Access can also be granted to anonymous users.
CSV data can be imported, with the UI supporting column mapping, data validation, and previewing prior to final import. If an imported row has a value for the Primary Key, the existing row will be overwritten.
Data can be exported to CSV, including after filters have been applied.
Records in tables with date columns can be viewed in a calendar.
Entity Relationship Diagrams (drawn with GraphViz) can be automatically generated, with any specified subset of tables. Foreign keys are displayed as directed edges.
All data modifications are recorded, along with optional comments that users can provide when updating data.
Tables with point columns can be exported to KML and OpenStreetMap XML. Also, data entry for these columns is done with a small slippy map, on which a marker can be placed.