FoxTrick enhances the user experience on Hattrick by providing tons of extra information, a lot of shortcuts, tweaks for the presentational layout of the web pages, analyses of matches, links to utilities on external sites, and provide browser-side alerts and notifications.
The only mobile browser which supports addons so far is Firefox. Hence, FoxTrick won't work on Opera mobile, Safari mobile or Chrome mobile!
There's a version available in which pure presentational modules have been removed to increase accessibility: FoxTrick light
Other than the stable versions, there are also builds of the next upcoming version. ONLY use it if asked by a developer or if you participate in bug hunting. They would contain latest features and latest bugs: FoxTrick Development Builds.