SymbolHack for

From Florent Pillet:

SymbolHack lets you quickly access hard-to-write symbols by popping up a symbols window whenever the Keyboard is accessed. SymbolHack provides for a configurable symbols table and optional screen positioning for left-handed or right-handed users.

The Keyboard is still accessible: simply tap the 'Keyboard' button at bottom on the SymbolHack pop-up window, and the original Keyboard is displayed.

Note that you can still directly access the Keyboard window by using the Keyboard menu command, or by tapping the hot corner of the Graffiti area that has not been assigned to SymbolHack.