Move #1 - 0 degree
Move #2 - 90 degrees
Move #3 - 180 degrees
Move #4 - 270 degrees
But would certainly need a lot more work to make it moves/trembles/shakes like a speedo meter in the car when you step on the accelerator....
The needle image is from https://github.com/jfryman/velometer
The loadView method of the view controller only did the following plus the button creation work:
myImageRect = CGRectMake(0.0f, 200.0f, 320.0f, 109.0f);
myImage = [[UIImageView alloc] initWithFrame:myImageRect];
[myImage setImage:[UIImage imageNamed:@"VM1_D.png"]];
myImage.opaque = YES;
Then when clicked, each of the button's action simple do the following, with different parameter used. #1 is "M_PI*0.0", #2 is "M_PI*0.5", #3 is "M_PI*1.0" and #4 is "M_PI*1.5".
[UIView beginAnimations:nil context:NULL];
myImage.transform = CGAffineTransformMakeRotation(M_PI*0.0);
Source Code for Speedo Meter Project (Updated)