Simple Soroban overview

This application is a simple Japanese abacus (soroban / そろばん). It has a free mode where you can use the abacus freely, and a challenge mode with 4 operations (addition, subtraction, one and two digit multiplication, and division) and 3 difficulty levels (easy, medium, hard) where you must race against the clock to perform calculations. Contains tutorials for: * basic concepts * addition * subtraction * one-digit multiplication * two-digit multiplication * division Also has a custom challenge mode where you can set the number of questions, type of questions and difficulty. (This is just a hobby project I'm doing for fun. This app is free and doesn't have in-app purchases or ads). [PERMISSIONS USAGE] This is a description of how permissions are used in this app. Vibrate: The application can vibrate the phone to give user feedback. This can be enabled/disabled in the Settings screen. [PRIVACY] This application does not collect or transmit any data. Your settings, ranking and challenge times are stored locally on your phone only. You can view the privacy policy here: http://bit.ly/simple-soroban-privacy