Flex 2 Beta. It's free right now since it's in beta but it'll be (I think) a $2 upgrade fee if you already own a copy and $4 for anyone new. I'm pretty sure it's always cost $4. I'm almost positive that's what I paid shortly after it first came out.
If you're on 6.x use the original flex. If you're on 7.x use the Flex 2 beta. I'll post the repo in one minute. Just gotta grab it for you.
Edit: the repo is
http://getdelta.co
Edit again: Is this your first time using flex? Normally, users can upload tweaks to the cloud and then anyone can download them. But right now while it's in beta and since he's making some upgrades to the cloud, users cannot upload tweak at the moment. Therefore, everything in the cloud is pre iOS 7. Some tweaks "may" work but most likely they do not. I've tried several of them and only got 1 to work.
For now, you can either try to create your own tweaks (extremely difficult if you have zero programming experience) or go hit up Reddit (this is the better option for beginners).
www.reddit.com/r/flextweak
Thats a subreddit for Flex tweaks. A lot of them give you step by step instructions on how to create the tweaks yourself. I couldn't make my own tweaks until I saw how this app worked and saw how other people created tweaks. After learning from them, I started to make my own.