I was very happy to see a post from ESRI appear in my feed this week about the new beta for Collector on Windows 10. It has irritated me that the only app available for Windows Phone was the ArcGIS app, which was pretty much a Collector app designed according to Modern principles anyway.
I am very pleased with this development, and am even more pleased that the app did not crash after I loaded it up on Astro. It only crashed while my colleague was attempting to navigate out of the Measure screen, but that could also just be my tablet acting up.
I will continue testing the app, hoping that related tables will appear soon, and that ESRI will turn into a universal app.