There was a policy change from Google for all apps requiring SMS related permissions as you can see from here.
I submitted the app for a review many times but they rejected it every time. I also tried submitting it with the instructional video featuring a demo page completely integrated with the app but they rejected the app without even looking at the demo.
This doesn't mean that the app will stop working. The app will work normally but it won't be available via Play Store anymore.
Unfortunately, This is out of my hand. I will provide update notifications through CodeCanyon. You can get the latest version of the app from here.
If you don't know how to sideload apps then you can follow this guide to install the APK file.
If you have any questions then you can contact Google Play support.