Chars.cc — iOS system-wide Unicode keyboard. It is a beautiful and native way to type everything with Unicode characters on iOS.
You are welcome to contribute Chars localization for your language!
It seems to be, en and ru localizations are reference files to start.
We are waiting for pull-requests.
Also, we are about to add more characters in keyboard set. If you have one, please write us an email: info (at) chars.cc