There has actually been something similar (even, a serious and real product that has been actively maintained for years and is being sold for $1.99) in Cydia (for jailbroken iPhones) available on iOS for a while now, in case anyone wants to try it on non-Android ;P.
April fools or not, if we're talking alternative fast input methods then why not remind people of chording keyboards[1]? Nice simple keypads ergonomically designed for comfortable one handed use with multi key combinations corresponding to letters / digits / symbols.
There was a trial a few years back by the University of Queensland marine division of an underwater system with HUD facemask display and a chording keypad so that researchers diving could hold specimans / tools whilst also looking up references / enter data.
Like a number of alternative key entry systems it was surprisingly fast once people became used to it.
Many high-speed CW (Morse) operators use devices with two inputs rather than one (called "iambic paddles"). See https://en.wikipedia.org/wiki/Telegraph_key for various types of Morse inputs beyond the traditional single key.
I find it kind of sadly ironic that morse code could actually speed up input, and perhaps shouldn't be treated as a joke. For example, a pair of telegraph operators beat "the world's fastest SMS texter" on Jay Leno a couple years back.
Kind of funny, but true we have to many buttons. Someone submit a application for a keyboard with less keyboard o YC. Also getting LL Cool J was a nice touch.
It's a real Android input manager, you can use it (more or less) as a real keyboard :)
The code is open-source: https://code.google.com/p/morse-keyboard/