Version 4.13 is official: https://plus.google.com/111815032990260235809/posts/2pzgQAxHQCj

Here are the changes since v4.12:

WEAR:
►Option to hide peek cards in ambient mode (Credit: Raz Pavel)

WIDGET:
►Fixed large letters bug on Jellybean phones (introduced in v4.12)
►”use highest res icons” option to revert to previous icon engine
►hide pencil on a per cloud basis
►set bubble spacing for each cloud separately
►clear individual cloud settings by setting them to the same as the default
►bubble sizes are now harmonized better when merging clouds (delete widget → “merge into”)