I've read that task killing apps on Android are unnecessary as the OS itself will auto-kill your least recently used applications when it needs more space. I have an S4 and if I want to kill an app, or all of them, manually you can pass and hold the home button for a second or two until the recently used app screen appears. Then in the bottom left there is a button to go to the task manager. From the task manager you can see all running applications and processes, and are given the option to kill them individually or all of them together. Sorry if that wasn't quite clear, I'm typing this on my phone and Husky is kind of a pain in mobile for me.
We have a Hubski mobile beta here: http://hubski.com/m/pub?id=131510 Just enter /m/ after the .com on most of the pages.