Train your Working memory!
This app is designed to train working memory. 5 minutes or more per day is recommended.It is a game that requires a great deal of concentration, so please limit it to about an hour a day.Added the level adjustment function that you requested.(Thank you for your patience.)The target API level has been raised from Android 4.4 to 10. (To comply with Google Plays policy.)Please be careful when updating.Other minor fixes have been made.