In case you haven’t followed the recent developments with Simple Mobile Tools: the entire set of apps was forked by Naveen Singh and is now called FossifyX - at least for now, there is a debate going on for which final name to adopt.
In other words, stick to the F-Droid version of Simple Mobile Tools until F-Droid picks up the FossifyX branch, and continue from there. With any luck, you won’t have to change any of the tools you’re currently using.