The Jmgo O2 Ultra 4K is a compact and stylish projector with great performance. Since it’s not made for the European market, Google Play isn’t available, but apps can be installed via ADB or with an Android TV box (I chose ADB). To stop apps from closing in sleep mode, use: appops set <package_name> WAKE_LOCK allow appops set <package_name> ACCESS_MEDIA_LOCATION allow appops set <package_name> READ_EXTERNAL_STORAGE allow appops set <package_name> WRITE_EXTERNAL_STORAGE allow "To keep Spotify playing in the background without being closed by sleep mode, I used these commands:" Sound quality is excellent, both through speakers and headphones. One quirk is that it never fully powers off, staying in hibernation. I solved this with a power strip switch. Overall, a solid projector once set up properly.

The device is just what I needed. I like the analog volumn control and the fact that the speaker remembers the mode.  The quality is good and the output is quite powerful. Best of all it matches my retro computer project.  Thanks again...