I mentioned in my cord cutting guide that I switched to Roku last year and sold all my Apple TVs. One of the things I do miss is AirPlay (when it works). AllCast for iOS is helping to bridge the gap, though. It allows you to cast your movies, photos, and music to just about any streaming device. It works with Chromecast, Xbox 360/One, Roku, DLNA compatible TVs, Apple TV, WDTV, and Amazon Fire TV.
In addition to being able to cast content from your device, you can also pull from Picasa, Google+, Google Drive, Dropbox, Facebook, Instagram, Plex, Serviio, and XBMC. If you store your photos on Dropbox or Google Drive, this will make it incredibly easy to share to your Roku or Amazon Fire TV. They also have an Android app in the Google Play Store.
The app is free, but there is an in-app purchase for $4.99 to remove ads, splash screens, and video length limits.