The famous (and imo, far superior) arena frame AddOn GladiusEx - now for Cata 4.3.4!
The AddOn will not work on Classic Cata, it will only work on the original Cata client.
The folder "GladiusEx-Cata-master must be renamed to "GladiusEx" and placed in /Interface/AddOns (relative the WoW root folder).
The "Cooldowns" module is only in beta mode. It works, but some abilities might be missing / having an incorrect spell ID (thus not working) / have an incorrect CD / be missing some conditional (e.g., lower CD if some other talent that we know is picked). Feel free to report specific improvements that can be done, or create a pull request.