[pasbesoin]

Just heard today about a phone app that helps the user practice CPR correctly. It even uses the accelerometer to measure the depth of compressions. (Apparently, there is a comfortable/correct way to hold the phone (fingers of upper hand) while doing CPR (heel of palm of lower hand).

It was mentioned on one or another public radio show, in an interview with a professor or authority in Wales. Actually, there are a few CPR apps; this one is called somethingCPR, IIRC.