Source code: https://github.com/minecrafter/RedisBungeeClean (Unlicense)
The way RedisBungee stores certain data does not make it fit to use the Redis expiration features (basically, you can't expire keys inside a Redis hash). RedisBungee can eventually store a lot of data in Redis (especially the UUID cache, which doesn't clean itself except for expired entries it finds for performance reasons), so there is a need to periodically clean the UUID cache.
This one-off tool cleans old UUID cache data by scanning and removing entries that are out of date. This tool should only be run rarely (perhaps only every few months at least): small servers will likely see less need for this tool due to fewer unique players.
See https://github.com/minecrafter/RedisBungeeClean#usage for usage instructions.
This is a command-line tool. I will not add a GUI to it, for very obvious reasons.