maybe it's possible to the following option can be added for pro version.. The option for recording the call logs for separate SIM cards to separate calendars on Google for a DUAL SIM Mobile.
免費版需要手動備份短信和通話記錄到Google Calendar 付費版3美元，先用用看，可以考慮打賞作者
HTC one Good app, but no-one uses sms anymore. Will buy if whatsapp messages can be saved.
Once work great Upgraded to nexus 5, not able to sync anymore. No error message prompted either.
Version 2.2.1f (2016/05/29)
- Fixes: not being able to save calls on recent Samsung phones
- Other minor bug fixes
This update is for Android 4.0+ devices only.