I currently use the Zoiper (free version) on my Nexus 5X (Android 8) phone for making VoIP calls over 3G. It's working fine but I am considering to improve the call quality over 3G, hence upgrading.
My questions are:
1. Should I just purchase the G729 Codec using free version
2. Upgrade to the Pro version: if yes, would it include G729 Codec
3. Last, would G729 make a significant difference in the call quality - like better the quality by 20%-30%