1./ If you want using Arduino board, I suggest Arduino Wifi Shield Board and I will build motor driver + Vibration motor board external, It is very small
2./ If you want have one board with Atmega controller + Wifi module + Vibration motor and more function ( ex: LCD display, Buzzer, LED light, ...). I will design for you.
3./ For Android app, do you have one android apps ?. If you have not any, I will build one Android apps with your board. Please let me know your requirement about Android apps ( Display, icon, ...)
Thanks & Regards,
Ty Le