Calls made through Another Number are of the same quality as calls made through your network if you set the app to connect your calls via the Mobile Network.
However, if calls are set to use 'Wi-Fi / Mobile Data', then the call quality will be highly dependant on your data connection quality.
You can configure this within the Another Number app -> More tab -> Make Calls / Receive Calls
thumbtel Support
Calls made through Another Number are of the same quality as calls made through your network if you set the app to connect your calls via the Mobile Network.
However, if calls are set to use 'Wi-Fi / Mobile Data', then the call quality will be highly dependant on your data connection quality.
You can configure this within the Another Number app -> More tab -> Make Calls / Receive Calls