Amungmiak

In this ad free pro version you can automatically save calls from a contact and add comment to a recorded call.
You can also stop a recording in progress or start recording when a call is in progress.

Record all desired calls on your phone.
Select which calls to record:
You can record all calls or only those that are from numbers that are not in your contacts.
You can play, save and share the recorded calls.

Please note that on some devices recording a call is no possible so please try the free version first.

Auto call recorder also supports wav , ANR, 3gp formats.
Recording on an external sd card or any location desired is also possible.
The audio source is now configurable.
For playing the 3gp format you can use the "MX Video Player".

If you have a problem with the recording, please try to record with a different audio source,
which you can configure in the settings tab.
Try to record with speaker on or off , until you find the best combination for your phone.
For example you can try Audio Source -> Voice UpLink and speaker off.