ACR (Another Call Recorder) is a free call recorder application. It is one of the best and most advanced call recorders in the Play Store and offers many advanced features such as:

Record any phone call you want and choose which calls you want to save. You can set which calls are recorded and which are ignored. Listen to the recording, add notes and share it. Integration with Google Drive™ and Dropbox allows calls to be saved and synchronized to the cloud as well.
Please note that call recording does not work on certain handsets and can result in inferior quality recordings. We therefore suggest that you try the free version before purchasing the paid app.
If you encounter any recording issues or wish to improve voice quality, try recording from a different audio source, or use auto-on speaker mode.
Recorded calls are stored in the Inbox. You can set the size of the inbox. The number of saved calls is limited only by your device memory. If you decide that a conversation is important, save it and it will be stored in the Saved Calls folder. If not, old recordings will automatically be deleted when new calls fill up the inbox.
You can enable a Call Summary Menu with options to appear immediately after a call.
Search for recordings by contact, phone number, or note.

There are 3 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.
In the Pro version only: You can set calls from particular contacts to be automatically saved, and they will be saved in the cloud.
This app contains ads.