A rooted Galaxy S1 with Android 6, if my code runs on it then it will run on anything.

Where did you get S1? it was a shit phone when it was released, and even more shit now.
and you are wrong btw. customized OS means nothing.

@magicMirror You must be a very fun person 😓

What if your app needs root permissions?

@jepp73 @demiko
S1 is shitty indeed. also 6 years old. I once installed a Custom Android rom onto a htc g3 device. the Rom was android 2.2, and because it had so little ram, it could only run one app at a time. This meant that you could run a launcher, OR your testing app. not both. The number of times I screamed at the poor QA girl.... QA on that device meant exactly shit.
And I never claimed to be a fun person. cynical, and sarcastic however...

@magicMirror I didn't get it, I kept it :)
The sluggishness of the phone is why I use it as a dev tool. It's a good way to analyze app performance. The "customised OS" is so that I could run my apps on it (since I set the minimum SDK to 19 or 21 according to features that I wanna include)

@billgates The ROM is rooted

@dannydam sounds like you know what you are doing. Good luck!

@magicMirror Thanks!

@dannydam I'm just saying... if you need to request root for your app permissions, not any device would be able to run it