How to install and use it?
1. Install addon.
2. Go to Admin > (sidebar) Appearance > Widgets > (top - right) Add Widget > Widget definition = Thread Prefix Widget
3. Form:
Widget key: sc_threadprefixes_cloud
Title: Thread Prefixes
Display in positions: Forum list: Sidebar (or somewhere else)
Maximum entries: Whatever you want (min:1, max:200)