Sorry for the late reply, had to work this weekend.
Anyhow, I did download the app you linked above, but it looks like you were right about it not working right out of the box.
As soon as I try to open it (on either phone -original or newer) it pops up a " IntroActivityX Couldn’t get superuser permissions " message and only lets me click " Ok " and closes itself as soon as I click it.
Before I click " Ok " though, I get a glimpse of the Welcome page behind that IntroActivityX message and notice it says;
Now, on the functionality of our App:
*It requires root and allows you to back up individual apps and their data.
*Both backing up and restoring individual programs one-at-a-time and batch backup and restoration of multiple programs are supported.
*Restoring system apps should be possible without requiring reboot afterwards, but still we don’t advise to do it.
*Backups can be scheduled with no limit on the number of individual schedules and there is the possibility of creating unique custom lists.
So It looks like I have to root both phones to use this App; something I can not afford to do at the moment in case I Brick the phone (due to me being a larvae for all of this phone & computer OS meddling that’s happening these days).
I also tried your steps, I think, and still didn’t work.