There are several apps for iPhone that allow you to control and use a computer using wifi. Well, today I came across an app- RemoteDroid for Android that allows you to control a computer using Android phone.
RemoteDroid is an application that can interface with your home computer (PC, Mac or Linux) and act both as mouse and keyboard. The mouse is operated using the trackball or the touchscreen and the keyboard on screen works as a keyboard for the computer.
To use RemoteDroid, first you’ll need to download a server application on the computer and then download the RemoteDroid app for your phone.