I'd echo what Jamie said. You can get some visibility on the Android side of things since Google can stitch that together easily. iOS is trickier. TBH I have

I'd echo what Jamie said. You can get some visibility on the Android side of things since Google can stitch that together easily. iOS is trickier. TBH I haven't done anything with that specifically yet, so not sure how great the solutions are out there. I'm sure you could do something with statistical modeling, just like anything else, but you need lots of data for that (and a skilled statistician or firm who does this).