@jojo2 While UT is a convergent OS, when running it on a mobile device your choices will be limited by the the architecture (arm64 mostly these days) and hardware (cpu speed, ram and storage size).
Having said that, there are a number of ways to run foreign OS or architecture or programs. For Android apps there is Waydroid. For desktop apps there is Libertine, and on some devices snap support. For foreign architecture appa there is WindeBox. And for full on virtual machines there is PocketVM.
Using any of these, your experience will vary depending on the app and your device.