App designed with calculate icon for private ( protect by pin code), "Vibrate app" will turn your phone to vibrate device, you can use it to test vibrate of phone, massage or do something you like, I have test on SamSung Galaxy, HTC, Sony, Xiaomi phone it worked well. Have fun with this tool :) #Features: Hide other eyes with calculator icon Test vibrate Massage More vibrate mode Thanks you for choosing our product!