Android: Similar to Quad Drawer, AppDialer is a launcher for Android that uses the old-school T9 keypad for input. The focus here is on speed and ease, as AppDialer thinks a T9 keyboard is faster for entry than a standard QWERTY -- and the search results update in real time as well.
Tap the app and it opens as a floating window, in which you can search for the app you are looking for or hit Clear to erase everything. AppDialer also shows the last few apps you opened in a quick-launch bar. It can also be added as a widget on any home screen, and my favourite functionality is the lock screen widget to open an app even faster.
The Pro version of AppDialer adds a quick panel to the notifications bar that lets you access your most-used apps easily. If you don't care for this functionality, the free app itself is pretty awesome.
AppDialer Pro ($2) [Google Play Store]