UPDATE: Works with all iOS versions up to iOS 10!
You will probably agree, that non-jailbroken iPhones with iOS 5 or 6 or higher have one common problem: they do not offer convenient in-call conversation recording! Personally, I wish that this function was implemented by Apple as it is very practical. Anyway, now there is a fix which will provide you with such ability and you will not even need to jailbreak your phone! It is made by a couple of guys from iNerd’s team so they know what they are doing. It looks like it belongs with the default iOS 5 or 6 since it is very well thought out and looks nice. Maybe it was a hidden function by Apple?
1. Launch the program.
2. Connect your phone. If the program does not recognize it, try to turn off the iTunes. Then click the red dot and wait for a few seconds. It is usually very fast.
3. Wait util it is done. Disconnect the phone and enjoy! You will see recording button when you call somebody.
Here is how the function looks on iOS 10. Tap the circle below the call timer to start/stop recording. You will find all your recordings in your voice memos: