The Samsung Galaxy S2 may have been long forgotten by the markets but the device is still rocking in the hands of a lot of people. For many, the Galaxy S2 was the reason they fell in love with Android. It was a pure performance phone, the only Android phone of its time that didn’t lag. And we’re happy to tell you that it still lives, rocking even the latest of Android updates.

CyanogenMod recently added CM 12.1 nightlies support for the International Galaxy S2 variant I9100. If you’re a seasoned user, which is very likely since you’re boasting a Galaxy S2, just grab the Android 5.1 Lollipop based CM 12.1 ROM from the download link below and flash to it your Galaxy S2 using a custom recovery.

Download CM12.1 for Galaxy S2 I9100 (Download the latest nightly build.)
Installation instructions
  1. Install a custom recovery on your Galaxy S2. For help, check out this page.
  2. Download and transfer CM 12.1 ROM to your Galaxy S2.
  3. Boot into recovery mode:
    1. Power off your device.
    2. Press and hold “Volume Up + Power” buttons together and as soon as you see the Galaxy S2 logo on screen, release the buttons. You’ll boot into recovery mode.
  4. Once in recovery mode, do a backup first and then perform ‘wipe data / factory reset’ from the recovery.
  5. Now install the CM 12.1 ROM (.zip) file using the install option on your custom recovery.
  6. Let the install finish and then reboot your phone.

CM 12.1 should now be installed on your Galaxy S3. Enjoy the Android 5.1 Lollipop goodness on your Galaxy S2 now.