[Oxodao]

I'd also like to fond one such youtuber. If you want to get started though your best bet is probably combining jadx-gui (an amazing decompiler targetting Android) alongside with apktool to disassemble / patch / reassemble your apk and uber-apk-signer to sign it back afterward with mitmproxy to snoop on the API calls. That's my setup whenever i poke around old apps and try to make server emulators for them. A really cool tool is also Frida and xposed which lets you quickly hook into the apps.

I'm pretty new to RE though this kind of videos are super interesting for me