Students at Columbia University are working on a new type of compatibility architecture that they have called Cider, which will allow iOS apps to run on Android hardware. The tech is still very much in development, as there is not yet support for apps that require access to certain hardware such as the camera, GPS, or bluetooth, but a video showing the proof of concept and basic functionality has been released. No plans have yet been released to make this project available to the general public, but should this project come to fruition, it could be a very handy way to gain access to apps that are available to all your iOS using friends that us Android folks wouldn't ordinarily be able to use. Very cool stuff. You can learn more and watch the aforementioned video.