iOS: WakeSmarter is a pretty great standard alarm clock that takes things a bit further by adding voice control, similar to what you'd find in Apple's Siri. When it wakes you up in the morning, you can ask it for information you want to know.
For example, if you're curious what time it is, what the weather's like, or what's been posted to your Facebook and Twitter feeds, WakeSmarter will respond with that information. All you have to do is speak a code word so it knows to listen to what you're saying, or tap the microphone button on the screen (although that's not as cool). What's also great is you can set that code word yourself.
In addition to the very cool voice control features, WakeSmarter offers a lot of what you'd hope for in a great alarm clock app. You can dim the screen by swiping up and down, choose your background, get woken up to a custom (or pre-recorded) greeting, switch between night and day modes, listen to music, and a lot more. Of course it does suffer from the drawback of all iOS third-party alarm apps, meaning it needs to be the foreground app to fully activate its alarm features. That said, if you don't like staring your phone in the face each morning and would prefer to speak to it to get the information you want, Wakesmarter is a good option.
WakeSmarter ($2.99) [iTunes App Store]