Typeeto - Use Mac’s keyboard to type on iPad, iPhone, Android, etc.
Type2phone - Type2Phone: Use your Mac as keyboard for iOS devices
1keyboard - Type on your iPhone, iPad or AppleTV using your Mac keyboard
across - Across makes a Bluetooth equipped PC or Mac work as a standard Bluetooth keyboard/mouse combo.
Synergy - Cross-platform software for sharing your mouse and keyboard between multiple computers
Unshaky - Dismiss duplicate key hits on MacBook butterfly keyboards