Yep, recent phone cameras and processing power advancements makes such a thing finally possible. I can confirm that with just 10 sec exposure I can stack my 4 years old Galaxy N7's images to reliably resolve even 9.5m stars.
Don't be fooled with the cheap price though, a capable smartphone, which is the most essential part of the system, would cost you quite a bit (all the way to over a grand).
The performance is also quite questionable given the diversity of smartphone cameras' focal rates and sensors density. But I think it should be on par with manual settings circles. From the video I can catch that they are using plate solving only on the initial and final stages, while in between they are using gyros/accelerometers.
Finally, the alignment procedure should exist as you need to figure how the phone camera is aligned with the optical axis. Most likely that's a 2 stars alignment procedure as the phone cradle looks quite generic and sorta flymsy, so it cannot reproduce or hold the alignment between phone re-insertions. But that could be within tolerances the app is aware off (but still that would affect the accuracy without the alignment).
The better but more expensive approach would bo to make individual/modular cradles for various phone models. That's also not ideal, as many folks using their phones in the field in protective sleeves already.
Fortunately, the Celestron construction is super cheap and overly trivial. So the potential for DIY improvements to the system is enormous (you can replace everything to your own design, including changing the mounting location). I have no doubt that the open source software (free of charge) doing the same solving is on the way as well (as luckily there is nothing to patent here except maybe that flymsy cradle ).
So, folks, it's time to upgrade your smartphones. I would highly recommend Android smartphones as they are the easiest for DIY modding. Stay away from tablets, it will be hard to mount them on smaller OTAs.
Regarding mating with the Telrad: not necessary, just get cheap +3.0 reading glasses with widest rimless lenses and remove one of them. I'm using that with my smartphone sometimes for like 5 years already. One eye looks into the EP, another to the star chart on the phone screen (that's not for pointing, but for ID/starhopping).
Edited by halx, 08 January 2020 - 01:14 PM.