Accurate: Confirms NRC-calibrated GCA-07 Geiger counter readings of:
CPM = 1412
mSv/hr = .01380
...Outstanding, accurate app for the price! I'm quite impressed that an exceptionally inexpensive iPhone cam can give comparable readings as a near $500 professional Geiger counter. Your Mom might have a hard time using a real Geiger counter, but she can annoy the heck out of you with her iPhone...! Now she can be safer in a nuclear-accident situation as well.