I used a rpa extractor program that I wrote up, sadly it will not work on a smart phone.
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Cannot give you my program (Honestly it's finicky as heck as I made it long ago when my coding skills were less than they are now. But on your pc here is a link on how to use a rpa unpacker program https://www.youtube.com/watch?v=lR0ClSGaffI The video has a link in the description where you can get the program itself I've tried their version as well and it works like a treat.
Hope that helps ya in the long run of unpacking those rpa files to get to the goodies inside.