AR Ground Plane Detector

Hello guys!

I need to check for a "ground plane" to put objects over it without a marker, using Unity3D.

I did test Vuforia on it, but the Ground Plane on Vuforia only works on some devices, I tested on mine and my mother's Android phone, both modern and from different brands, didn't work at all. So it's not an option, because many many people couldn't use it...

Same with ARCore, asked me to install some sort of Google Services AR, which the download is locked for my phone.

Is there any way to use Unity with some kind of ground plane detector that many phones could track it? Any API, code, anything different that I didn't try yet? I just need to track a plane without a marker! Or something that can fake it in some way, that's ok too. Any ideas?

Thanks a lot!