if u want to using buttons use this it will work in unity 3d and ios
void OnGUI()
{
if(GUI.RepeatButton(new Rect(50,210,40,40),"up"))
{
transform.Translate(Vector3.forward*Time.deltaTime*50);
}
if(GUI.RepeatButton(new Rect(50,280,40,40),"down"))
{
transform.Translate(Vector3.back*Time.deltaTime*50);
}
if(GUI.RepeatButton(new Rect(10,250,40,40),"left"))
{
transform.Rotate(Vector3.down, 90*Time.deltaTime);
}
if(GUI.RepeatButton(new Rect(90,250,40,40),"right"))
{
transform.Rotate(Vector3.up, 90*Time.deltaTime);
}
}
other wise,
u can use joystick for the movement in ios. the standard package is present in standard assets mobile in the unity itself.
so u try it once.
In menu->assets->import package->standard assets(mobile)