Dropbox
8tracks
???
Some of my favorite ones are: Todoist - to do list app, good interface with reminders and things. The paid version is like $30/year so I've just stuck with the free one for now. Pocket Casts - I don't know is you listen to podcasts but this is a great app for finding, downloading and listening to them. I think I paid $3 or so for it. Simple Rockets - not a utility app but a great game where you build and fly rockets. It's like a 2D Kernan Space Program. The developer seems like a good guy too, a few months ago he gave out all of his games for free. If I think of some more I'll add them.
Evernote or other notetaking app. Something to auto kill all running apps (is this still a thing?) Hubski bookmark on your home screen. :) banking app? mint? I don't know. This is what I use on a day to day basis: evernote, dropbox, facebook, feedly, spotify, twitter, angry birds, chase, imgur uploader, mint, piwik mobile, whatsapp, google hangouts app
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.
I use advanced task killer. For me, I use flipboard a lot. Super Hexagon, fo sho. Reddit flow. Read mill. Used to have twitter, but I don't like it anymore. And then a weather widget, and Google maps, because I spend half of my life on the bus.