hello i have a game done with unity on pc/mac standalone how can i manage to convert the mouse/keyboard input into touch based sens and add an accelerometer to the game… all i want is to play it on android smart phone i have unity pro trial for now. the game is an fps shooter game ty
You need to use a controller for android instead for the PC controller.
Also all things you use your mouse for must be converted to touch.
The system in Unity3D is kind of bad in this, but its getting better.
But I use Playmaker for all interaction. It is 1000% better 
There is no easy solution for this, if your game was not made with Touch input in the first place. you will have to replace/rewrite/refactor much of your input code to make it work properly.
For example, you don’t have mouse over/mouse look on Touch devices. When you move the camera look with your mouse, you do it when the position changes. This doesn’t work on Touch input, as a touch is only registered when you touch the screen, which is at the same time also registered as “click”.
Genereally also the OnMouseXXX Events won’t be triggered when you touch them. So it’s not as easy as add a script and all your problems are solved.