Simple NFC App Developer for Android

I need an Android app that needs to do the following:- - When the app is turned ON, it scans for a NFC tag every 30 sec (user adjustable) - If it cannot find any tag after 2 scans (user adjustable), phone would trigger an alarm - App must be compatible with all NFC supported android phones To give a better picture, a phone is on display on a table and no one is suppose to touch the phone. An NFC tag would be attached to the table and the phone would be on top of the tag. If someone moves the phone, the phone would set an alarm. Please be reasonable on the bid since its a simple app.