Kotobaten is a Japanese vocabulary language app that I've used as my daily driver for a few years now. It helps me keep track of words I want to learn and make sure I retained the words I already learned.
It's also my main sandbox for keeping my technical skillset sharp and experimenting with new technologies. Currently, the app is built with:
This has been an amazing project to help me grow and push me to expore areas I otherwise wouldn't. E.g., the Kotobaten apps are published on Play, Microsoft Store, and App Store, which helped me get exposure of all the store ecosystems. The app is also connected to Mixpanel through Segment, helping me learn new analytics tools.
You can find the source code for the Flutter app here.