This is a review for the RGT system as a whole, since both apps are necessary. I tried this with my Assioma Duo power meter pedals, a CycleOps/Saris Hammer H1, an iPhone 8, and iPad Pro 9.7. My internet is fast enough to stream two 4K movies at the same time. I have no problems with Zwift, TrainerRoad, Rouvy, or Xert with my setup. I’m pretty disappointed with RGT, but at least I didn’t spend any money. You might have a better experience if you have different equipment, but I’ll bet that most people will be frustrated with this and go back to Zwift.
The good: the routes are based on real places, they have a free tier, and I was able to get the basic functionality working so that I could ride (power measurements and pairing the two apps together). That’s it for the good stuff.
The bad: The screen freezes occasionally, which is annoying. There is no power match feature (using the Assioma power measurement instead of the Hammer’s). In fact, I can’t even connect the Assiomas and the Hammer at the same time, it’s one or the other. When connected to the Hammer, the cadence is about 1000x higher than the true cadence (like it will read 88768 rpm). Erg/sim doesn’t work- when going up a hill the trainer doesn’t increase resistance, so it’s like I’m hooked up to a dumb turbo trainer. So the cool features of having a smart trainer doesn’t work.
I realize that it might work better with a different trainer, but my trainer works fine with every other app and can’t be responsible for all of the bugs and can’t be to blame for missing features like power match. RGT has been out for well over a year, but still has a long way to go before you should consider it as a viable alternative to Zwift.