A word of warning. The apps didn't work properly on mine, so I did researched a bit. It seems that many devices don't come with drivers that enable proper call recording. I found out that for those devices (including mine, a Nexus 5), either the speaker needs to be enabled (not suitable for private conversations or public locations) or you need to root your phone and install better drivers (not suitable for me). Also, many devices don't support recording from hands-free devices such as Bluetooth.