Lemmy seems like the right place to ask this. Personally I’ve really enjoyed Gurgle, which is a FOSS Wordle clone app.
Additionally, if you’re into mapping, give QGIS a try.
It’s an open source geospatial data management application, which is available cross-platform.
It neatly integrates many processing tools into a relatively intuitive GUI, and having even some basic skill can lead to some job opportunities.
You can even import OSM data through plugins or download services, which you can use for all kinds of fancy things.