With the tireless efforts of some developers, the Galaxy S II and Galaxy Note 3 unofficially ported Android 10-based LineageOS 17.1. The Galaxy S II was released in 2011 and its latest official update is Android 4.1.2 Jelly Bean, released in 2013. The Galaxy Note 3 was released in 2013 and the latest official update to Android 5.0 Lollipop was available in 2015. Samsung has since abandoned official support for the devices and has not provided them with any further software updates.
Nine years after the release of the Galaxy S II and seven years after the release of the Galaxy Note 3, it is no surprise that the Android development community is still providing support for these two cross-device spdy devices. And the community’s evidence also shows the popularity of the two phones. Android 10-based LineageOS 17.1 has not yet been officially released, but unofficial versions of some popular devices have been available.
However, there is a problem with the Android 10 port of Galaxy S II. Radio interface layers (RIls) are not stable, which means that people may not be able to make calls or use mobile data, which essentially prevents people from using this version for everyday use. But the Android 10 version of the Galaxy Note 3 doesn’t have such a problem.
You can download the Android 10 LineageOS 17.1 version for Galaxy S II and Galaxy Note 3 here.