WolframAlpha quicklaunch for Android keyboard installation.

Menu > Settings

Goto 'Local & Text' or 'Keyboard' Depending on your device type.

Check the box for Math Keyboard. Don't worry about the pop up, if you are afraid the keyboard is a key logger don't use it for important info!

Now goto a text field and touch and hold it to get this context menu

Select the Math Keyboard and now you are good to go!