I just ordered one of these on Ebay. I plan on using it as a general app machine, not as a phone. It won't be activated. My question is this--- regarding the GPS-- If I were to purchase one of the map system apps, will the GPS work on this phone like a normal GPS?...... Since I won't have any 3G/4G or voice connection. Also---- I read a spec that says this thing holds a "mini-SIM". The Ebay ad said nothing about a SIM. Am I safe in assuming that this mini-SIM (if it even has one) won't be needed just to run it as an app machine? In other words, will the phone power up and run without it, or will I get annoying "insert SIM" messages?