Simple things like:
Spodcast, a Spofify->RSS bridge [1], made it because I listen to netcasts while working outside out of network reach (forest and field work).
Reader, a native-look epub/pdf/cb[rz] reader for Nextcloud [2], made it when my daughter was issued an iPad at school on which she was not allowed to install any "apps" while I thought the thing was tailor-made for reading books. The iPad was returned years ago but I recently updated Reader to make it run again.
...and a host of small tools which I make just when I need them, dumping them to GH for all to peruse, e.g.:
ZMapi, a Zoneminder CLI tool [3], made it when I installed a video surveillance system in the new barn which uses Chinese cameras which I do not want to be able to access the 'net directly.
bs, a Bookstack API CLI tool [4], made it when I needed to upload a large number of conference videos to a Bookstack site.
...etc
I don't have much time for these side things since I'm mostly busy on and around the farm but every now and then the weather is a good excuse to keep me inside...
[1] https://github.com/Yetangitu/Spodcast
[2] https://github.com/Yetangitu/files_reader
[3] https://github.com/Yetangitu/zmapi
[4] https://github.com/Yetangitu/bs