This incomplete Android app was an attempted prototype at a drag-and-drop Algebra game. I abandoned it mid-2014 when I realised that I needed to know a lot more about writing drag-and-drop interfaces before I could make this work - I subsequently began work on FridgeLogic as a way of learning this.
There's not anything in the way of setup instructions here - I recovered this from a SVN archive I found lying about whilst clearing out an old HDD in 2019. However, all the Android Studio boilerplate is there so hopefully it shouldn't be too horrific to import.