It’s called Iconical.
This app also allows you to create shortcuts for just about anything including the tweet screen on Twitter so you no longer have to launch the app and then pull up the space for a new tweet. Then you are also able to add shortcuts to call or FaceTime your contacts.
There are currently over 14,000 apps that this release supports.
The downfall of this app is that it is not free and will cost you $1.99 to download. Advice: Check out the ratings and read reviews left by other users to see if this app provides the goods that you are looking for to customize your phone or iPad further.