The current version 2.5 is a minor update to its predecessor 2.3. Functions, design and file format are the same, except for the following differences:
– More accurate nanolooop-to-nanoloop sync
– “Load on first beat” option for loading patterns
– Preview load in song editor also loads empty patterns
– Pattern length in song not fixed to 16 steps
– Song can start immediately or in sync with current pattern
2.5 carts contain a new flash chip. The 2.5 software is compatible with the new chip and the old one, so it can be installed on 2.2 / 2.3 carts, too.
via Nanoloop 2.x Versions.