Flashcalc Anzan is an Android application designed to help users improve their mental arithmetic skills using an abacus and Asian soroban. The app focuses solely on addition, which is the basis of other operations such as subtraction, multiplication, and division.

To start the exercise, users can program the numbers, the number of digits, and the time between two digits in milliseconds. After pressing the start button, users can add on a mental abacus and imagine the movement of pearls. The calculated sum can then be checked. The app features a sound "beep" to distinguish two similar numbers that follow each other too quickly to be noticed by the eyes.

By regularly training with Flashcalc Anzan, users can enhance their mental arithmetic abilities and improve their mental retention and imagination. Overall, Flashcalc Anzan is an excellent tool for individuals seeking to develop their mental arithmetic skills.