[floki_916]

My phone is hacked and being controlled by someone else. My settings keep getting changed on their own and a bunch of other weird stuff is going on. I need help. I believe it has something to do with firebase. I've tried factory reset and it doesn't help. I can't use adb because I can't get windows, Linux or OSX to recognize my phone.

[Rukbat]

You mainly rely on knowledge. If you aren't knowledgeable about phones, you pay a repair shop that has someone who is - to examine the phone and find out what the problem is.

Hacking a phone isn't a trivial thing, like running a "hacking app", or some other "magic". (I say magic, because "a hacking app" would be magic.) Almost every complaint we see here about "my phone is hacked" turns out to be not understanding what's happening, having gotten malware on the phone, or something similar.

Unless you're working for the NSA or some other top secret organization, and there's a reason someone like the Chinese or Russian government would be hacking your phone. But then you'd laugh at them and block them.