The Nokia Lumia 525 is now being updated to Windows Phone 8.1 with the arrival of its Lumia Cyan update. Its predecessor, the Lumia 520 has gotten the similar update earlier this week. If your Lumia 525 hasn’t received any notification yet, you can check over at Settings > Phone update.
So far most of the Windows Phone 8 smart phones have already gotten the Cyan update. What’s left is the Lumia 620, Lumia 720 and Lumia 820 which should be updated very soon.
Thanks @chapitkenchoro for the tip!