Typeeto - Use Mac’s keyboard to type on iPad, iPhone, Android, etc.
Synergy - Cross-platform software for sharing your mouse and keyboard between multiple computers
1keyboard - Type on your iPhone, iPad or AppleTV using your Mac keyboard
Input Director - Control multiple windows systems with one keyboard/mouse. Share a keyboard and mouse across multiple windows system.
KeyWi - Use your computer's keyboard to type on your iPhone or iPad
Ultramon - UltraMon is a piece of software built to help with the management of multiple screens on the same computer system. Without software like this, taking full advantage of an expanded desktop space can be difficult.