apk link: https://drive.google.com/file/d/1QRIkolrPcMXBGp5_A2aAuELlIB4r3fSy/view?usp=drive_link video demo: https://drive.google.com/file/d/1LDnoXthsjgrFu7q_qf9R4VOW74Vlw0Ff/view?usp=drive_link
This application takes the input from user and automatically updates the output. It uses a library called rhino-android for calculation of the expression.