One UI is an add-in Weather Icon Set for Chronus, Crius and the CyanogenMod's cLock Home & Lock Screen Widget.
Installation
1. Chronus Weather Icons - OneUI theme isn't a standalone weather widget, make sure you have Chronus/Crius/cLock installed.
2. This theme is only supported on OS 3.4 and later.
Credit
Chronus: Home & Lock Widget can be found at Play Store. All credit goes to DvTonder for his great widget.