Korean learning apps?

Does anyone know of some good apps for learning Korean? I've searched in the app store but none of the apps I've tried have been very useful for me. I'm particularly interested in apps for learning and practicing the hangul alphabet at the moment. I use android but I'd be interested in any apps you could suggest.

I'm also trying to learn korean and i usually do it on the computer so I enter http://www.talktomeinkorean.com and they also have an app så that you can listen to their lessons on your ipad/iphone. I actually dont know if that app exist to android but i know it works on iphones ^^ the name on the app is the same "talktomeinkorean"

Yeah I'm planning on going there next year, I was supposed to go there this year with my friends but my eomma said im too young to go there alone without any adults. ;-; So I'm going next year with other friends ^^ I'm only on lesson 16 or something, Ugh, but i think that i've learned a lot. I can understand part of songs and sometimes when i watch shows without subs I do understand what they say! :D