Uniconsole

Personalize your messages, e-mails and tweets with all kinds of special symbols and characters, which will be readable on any iPhone, iPad, Mac, and most PC applications — along with emoji, which are compatible with other iPhones and iPads.
Uniconsole gives you several pages of quickly accessible symbols; you can just touch a symbol and quit the app, it's already in your clipboard, ready to be pasted anywhere you want it. Or you can use Uniconsole's text field to work on a tweet, mixing text and symbols, and copy the whole text when you're done by touching the big scissors. Tap-hold the scissors for sharing options, including tweeting right from the app.
You can customize the first page of symbols by tap-holding a symbol to add it to your favorites; apply fancy filters to any text you've typed; access a detailed list of pretty much every special character that can be displayed on the internet.
You can also enable a systemwide custom keyboard that will give you access to all Uniconsole's symbols (your favorites, common symbols, and the full list as well) within any iOS app.
Uniconsole is a universal application that you can download once and install on your iPhone, iPod touch, and iPad.