When clicking on the bell next to your username in IC2, you can scroll through all the new features from January 2018 (InControl 2.5.1).
Older release notes you can find back on the forum:
There was no official 2.5.0 release. Due to the amount of fine-tuning and adjusting all the new features during staging faze and testing, it was decided to call it immediately 2.5.1.
