OmniROM was an incredibly popular custom ROM back in the day, and it may surprise you to know that it's still under development. The project is making headlines again for a new port by Max Weninger (maxwen), which brings the software to the Raspberry Pi 4.
Even though the Raspberry Pi uses the same ARM architecture as most Android devices, porting Android to the Pi has always been a tricky process, mostly due to missing drivers. There have been a few different attempts to bring Android to various Pi models over the years, but the new OmniROM port appears to be one of the most polished builds yet. It's based on Android 11, and is designed exclusively for the Raspberry Pi 4 — those of you with older models will have to stick with other operating systems, at least for now.
The ROM runs Android in tablet mode, and not as an Android TV device. That's likely a better fit for the Pi, which is typically used as a productivity/learning PC, though it would be interesting to see an alternative Android TV build at some point. Weninger noted in a forum reply, "I really don't think a raspi is a well equipped device to be used for ATV when you [can get an] ATV USB stick from e.g. Xiaomi for about 40E that simply works without issues and has official Google support."
The forum thread for the ROM says hardware-accelerated video playback is currently missing, and Mesa support for 3D graphics is a work in progress. Android typically doesn't work well when booting from slow storage like SD cards, but the ROM thankfully supports running from either USB or SD. The weekly builds also work with Gapps packages, so you can use the Play Store.
If you want to learn more, or download the ROM for your own Raspberry Pi, check out the source link below.
- XDA Forums