Recover files of an App

My phone is a Motorola MOTO G (first generation). Due to some troubles, I had recovered the factory settings of my phone. But I forget to backup some data of an app (Tricount). A this point my phone was not rooted.

My question is: is it possible to recover the data files of this application?

Currently, I just rooted my phone and I am currently making a RAW copy of the android system using command adb shell su -c "cat /dev/block/mmcblk0" | pv > mmcblk0.raw. My idea is to used extundelete command to recover the files after extracted the partitions using Testdisk.

Do you recommend to search files in a specific partition? I am not really familiar with the android filesystem...