DVR:

i.TV

While the main functionality of the iTV application is to provide TV / movie listings, it also has the ability to do remote scheduling for network connected TiVo DVRs.  It also acts as a remote control for TiVo HD DVRs and Roku players.   While TiVo is taking their sweet time in releasing an official DVR application, this app makes for a great substitute.  Link (Free)

Comcast

I rarely find people that are fans of Comcast as a cable company, but at least they have an iPhone / iPod Touch app for their userbase.  The application has a DVR manager (available in select markets) as well as integration into other Comcast services including Digital Voice for phone calls, Smartzone for email and On Demand for watching trailers.  Link (Free)

Dish Network

Continuing the lineup of television providers,  Dish Network’s official application integrates into their DVR service (assuming that you have an approved receiver unit).  You can schedule recordings, manage the priorities of the recording unit and browse through the program guide.  Link (Free)

Direct TV

Sleeker design than Dish Network’s application, Direct TV also provides the same functionality.  It handles all the same DVR functions and can be programmed all over the mobile device.  It works over wi-fi, 3G and the Edge network.  Link (Free)

SlingPlayer Mobile

If you have a SlingBox, then using the official SlingPlayer Mobile app to record all your shows is vital.  Interestingly, the core feature of the application is to wirelessly stream all of your recorded content onto your iPhone / iPod Touch via WiFi or the 3G network.  The 3G streaming certainly isn’t perfect, but having your entire library of media from anywhere outside of your home is an outstanding achievement.  Link ($29.99)