Blockbuster was acquired by Dish back in 2011 after filing for bankruptcy in 2010. The defunct movie rental company has had a desktop app, Smart TV app, and Android app since January and has now added an iOS app to the line up. The new app performs the same functions as the other currently available apps.
Users are able to browse, rent, then stream movies from Blockbuster's catalog of almost 5,500 different movies. Pricing ranges from $2.99 all the way to $6.99 for new releases. You'll need a free account, which you can create through the app or on Blockbuster's On Demand website.
Blockbuster has some competition in the streaming market. Netflix is rather well established and Redbox has recently entered into the market. It's going to be an uphill battle, but definitely doable. The app is available from Apple's App Store.