Samsung Galaxy S5, Note 4 and Note 3 has built-in call recording feature, but Samsung has not activated the feature for specific reasons. If call recording is legal in your country, you can easily enable the built-in feature by simply installing “Native Call Record” app on your Galaxy S5, Note 4 and Note 3(Lollipop), however your device must have root access.
Developed by the recognized XDA contributor dr.ketan, the “Native Call Record” app replaces “Add call (+)” button with “Record” button on the call screen. By simply pressing the record button the phone will record the phone call. A word of caution though, recording your own phone calls may not be legal in your country.
How to Enable Built-in Call Recording on Galaxy S5, N4, N3
Note: Before installing the app, Note 3 users should be updated their device to Android 5.0 Lollipop.
1. Download Native Call Record [HERE] app and install it as regular APK
2. Open the app and you will see two options: “Enable manual record” and “Disable manual record”.
3. Long press on “Enable manual call record” to enable call recording. (Do the same to disable the recording feature)
4. Grant SuperUser permission when asking and then reboot your device.
5. Now, you will see a record button instead of “Add call (+)” button on the call screen of your Galaxy S5, N4 or N3.
6. Now, you can uninstall the app from your phone.
Call recording capability on your Galaxy S5, Note 4 and Note 3 can be useful in many situations. If your device is missing this feature, there is plenty of third-party app available on Play store in both free and premium features. (source –XDA)