POSP aka Potato Open Sauce Project has made its debut a couple of years ago in the AOSP (Android Open Source Project) world that offers a minimal yet beautiful aftermarket Android firmware for a clean & buttery smooth user experience. POSP came with Android 9.0 Pie and currently offering Android 11 ROMs for various devices. You can also Download POSP OS (Potato Open Sauce Project) and check out the supported devices list.
It’s also needless to say that if in case, your Android handset has completed around 2-3 years from its launch then the chances are high enough that your device model won’t get the latest Android OS updates officially anymore. So, if that’s the case with your device model and you’re still going to use it for another year or so then it’ll be a good idea to use a custom firmware such as Potato Open Sauce Project.
Although you’ll have to unlock the device bootloader first if you want to install any of the Custom ROMs (Aftermarket Firmware) on the Android device, the POSP ROM will offer you a smoother UI with plenty of customization options built-in. A huge thanks to the POSP team for making such an amazing third-party firmware of a couple of Android device models and even if your device isn’t listed right now, then don’t worry as the developers are quite active.