You can automatic call recording and save any phone call you want.
You can record on SD card (external card) to get extra memory if your internal memory is low.

There are 5 default settings for automatic recording:
Record everything (default) – This setting records all calls except for contacts pre-selected to be ignored.
Ignore everything – This setting records no calls except for contacts pre-selected to be recorded.
Ignore contacts – This setting records all calls with people who are not contacts except for contacts pre-selected to be recorded.
Record incoming calls
Record outgoing calls