Howdy! LOVING MIT App Inventor, TYVM!
I want to build an app that will use NFC, or RFID, or BT to measure/know when User travels, for example, 2 meters away from phone. When User travels farther than set distance, phone will make sounds and/or vibrate. I want an app that will make it impossible to walk out of a room and leave my phone laying there. Need to be able to set distance according to surroundings/danger. If I'm at home, I would set it to 2 or 3 meters, but if I were on the Subway, I'd set it to .5 or 1 meter to be sure my phone never leaves my pocket.
I made a neat little App that uses Proximity sensor and it works great, but this will only measure in cm, uses sensors to measure how far away your face is from the screen. I need a sensor in my pocket or wallet that will allow App/phone to measure distance I am from my phone. TYVM!