iOS: Third-party keyboards in iOS didn't quite live up to the hype for most of us, but ReBoard is a new keyboard that takes a different approach. The keyboard features a lot of links to other services like Wunderlist, your calendar and Dropbox so you can easily send data from one app to another.
ReBoard's main appeal is its "command" function. Tap the Command button, and you instantly get access to a menu to search the internet, perform basic calculations, perform translations, search the map, your music library and more. Since it's a keyboard, it works in any app. Beyond that, you can also instantly add calendar events from any app, search and link to Dropbox files, and add tasks to Wunderlist. Unfortunately, you have to pay to add some third-party services to mix, but the core group of apps is enough for most people. As an actual keyboard, it's not particularly exciting, but as a means to quickly access other apps, it does its job.
ReBoard ($2.49) [iTunes App Store]