Two "would-be-nice-to-have" apps:

MediaPortal controller/client like aMPdroid for android. It uses MpExtendedService as a backend which has a somewhat documented API. Even just the WifiRemote part would be awesome.

Also nice would something like HomeBuddy which controls MiCasaVerde Vera home automation gateways. Vera also has a documented API. Here is an UI example.