WhatsLock - Lock, Password, Error Whatsapp /Apps

Nobody can open your whatsapp. Yes, this can be done on android devices. You can show error when openning whatsapp. You can write your own text in errror or you can just display password while openning whatsapp. If you choose error you can tap 5 times in 3 seconds to make password visible. If this is not done , someone trying to open your whatsapp sees something like error and closes it again.