Keycard from Appuous is advertised as an app which keeps your Mac protected by locking your OS X user account automatically when you’re away from it. It does this by using your Bluetooth connection to check for your iOS device’s (iPhone or iPad) presence, thereby detecting when you’ve stepped away from your computer or come back to it. Unfortunately, this sounds good only in theory.
To be fair, the idea seems pretty cool as the app turns your iOS device into a virtual ‘keycard’ of sorts. The execution, however, is terrible. There are glaring issues you will come across.