|This is an explanation of some of the features; this is also altered a bit for my own UI.|
JS' Hunter Bar is an addon that provides a lot of hunter utility in a small package. It's highly configurable, so even if there's things you don't like about it, you can remove or change them.
The addon is basically a moveable graphical display. It shows timers and durations of short-term buffs and procs, along with a more visible focus bar, autoshot swing timer and spec-specific build-up display (for BM, this means it will track Frenzy stacks). It also has moveable pop-up icons warning you when your opponent has something that should be purged with Tranquilizing Shot (ex. an Enrage on a warrior or boss), in addition to having a nice "trap duration" icon warning you of your triggered Freezing Trap's duration. With this addon installed, there's also the option to cast Misdirection onto your raid/party members or pet simply by right-clicking their raid or party frame, as well as options to announce Misdirection (and failed Misdirection due to mounted target) to party or raid.
Last, but certainly not least, there's a popup in chat informing you (with spell links) of what exactly your Tranquilizing Shot has purged, and off whom. You can configure this to announce to raid, chat, yourself in /whisper, or auto-chat depending on your group type.
It's got a lot of utility packed into a very small addon, and I strongly recommend it for all hunters!