Update: version 2.2.1 just released on the Store fixes the issue described below. If you are still experiencing any problem after upgrading, please do contact me.
Due to a major screw-up across the board, the latest version of KanjiBox (2.1.4) crashes on all devices running iOS in Spanish (no matter the country).
Help (and a bug-fixing version) is on the way (as soon as Apple approves it). In the meantime, you can read here on temporary tricks to work around the problem.
As always, do not hesitate to contact me if you run into any issue while using KanjiBox.
Sorry about that.