Here's a few helpful ones:

Call Confirm - I started using this when one accidental tap to update a phone or contact's email address caused me to call them instead. It causes a second prompt to show up asking "do you really want to call" just in case you accidentally tapped the wrong button on a contact list.

Should I Answer? - Want to block a number? This does just that in case some automated machine keeps calling you. I had this happen to me and it was driving me a little crazy, so when I told them TWICE to put me on their do not call list, they kept calling me anyway, so I put this into action and it's stopped the nonsense perfectly.

Zedge - Loads of great wallpapers, ringtones, notification sounds, and other stuff.