iOS

• 
  iPad

  CineXPlayer for iPad

  buy $3.99

  CineXPlayer frees your iPad from iTunes, by letting it play videos in just about any format, including 720p HD files, and quasi-3D Xvid movies. Want to add videos? Download them from the web from your own local or networked drives, or even from a Dropbox account.
• 
  Universal (iPhone + iPad)

  HBO GO

  get itFree

  Now that you can take "Game of Thrones" with you, those long trips on the Kingsroad or across the Narrow Sea will suddenly seem much shorter. HBO subscription required, natch.
• 
  Universal (iPhone + iPad)

  Netflix

  get itFree

  We're still waiting for the promised upgrade to HD for Retina iPads, but in the meantime, Netflix's vast selection, ease of use, and stable performance will keep us watching SD videos.
• 
  iPad

  Amazon Instant Video

  get itFree

  Amazon takes on Netflix with easy access to its streaming Prime Instant Video service, along with the ability to stream or download premium videos. One downside: You can't buy or rent pay videos from within the app, but have to do so via a browser and then come back to watch them.
• 
  iPhone

  CineXPlayer for iPhone

  buy $1.99

  Like its iPad sibling, CineXPlayer for iPhone lets you play video formats orphaned by iTunes, opening your iPhone (or iPod touch) to sources outside of Apple's ecosystem. Adding videos is easy, and you can even use iTunes itself to sideload them.