I don’t understand what is meant by “premium”. As far as I understood, it is FLOSS. “Premium” sounds like a Freeware with a Shareware companion, adding paid features. Or a fork of a OSS with added paid features.
What is meant by “premium”?
What is meaning of “should have”? Promised to be delivered with? Or desireable to have (but out of reach for whatever reason)?
Like SWEBkM, I also installed QKSMS, and it likewise has a clickable “backup now” button (not just a lookalike background graphics). But it doesn’t seems to share the SMS messages, instead it starts with an empty message board. Of course, this means, the working backup feature currently makes a backup consisting of 0 messages. There is an option in its Preferences menu (at the bottom, the next to last entry above “about”), saying “synchronise messages; matches messages with Android SMS-database”. (UI text translated back to english by me.)
Choosing it let the message board remaining empty.
What is meant by synchronising messages with Android SMS-database?
QKSMS asked to become standard SMS app. I agreed.
The build in message app (QKSMS fork) asked to regain standard app upon next start. I agreed. What a crap! Now both apps are “synchronised” on the lowest common ground, meaning ALL MESSAGES SEEMS TO BE LOST. Doh!
This leads me to the final topic: Where are the messages saved? I looked for directory names with “QKSMS” in its name (done before installing not-forked-QKSMS) and found two:
Both of them contained no data (except an empty folder named “Backups”).
How to locate folders where this/an app stores its data? Maybe I could scrape together some residuals from TWRP …
To clarify: Sadly I wasn’t aware of that I have no backup of SMS data, when I updated from Pie to Q the same way as updating a monthly minor release – i.e. only reset dalvik cache from within TWRP. This went not so smoothly (UI boots up, but phone calls doesn’t work anymore). So I tried to go back to Pie – but this works even worse (UI doesn’t boot up, but instead after some minutes leads back to TWRP). So I flashed Q again, working as well as before.