double rotation = angle - lastAngle;
selectedMob.rotate((float) (rotation));

public void rotate(float angle) {
    this.angle += angle;
}

double rads = Math.atan2(dy, dx);
                double angle = Math.toDegrees(rads);

09-13 00:03:53.708: V/GameActivity(23389): updating frame
09-13 00:03:53.708: V/GameActivity(23389): checked for all mobs
09-13 00:03:53.825: V/GameActivity(23389): Angle of finger is 360.0
09-13 00:03:53.825: V/GameActivity(23389): Angle of mob is 344.94818
09-13 00:03:53.825: V/GameActivity(23389): Last angle is 359.56921278299137
09-13 00:03:53.825: V/GameActivity(23389): Rotation will be 0.43078721700862843
09-13 00:03:53.825: V/GameActivity(23389): ****************
09-13 00:03:53.825: V/GameActivity(23389): updating frame
09-13 00:03:53.825: V/GameActivity(23389): checked for all mobs
09-13 00:03:54.137: V/GameActivity(23389): Angle of finger is 0.4275725068334077
09-13 00:03:54.137: V/GameActivity(23389): Angle of mob is 345.37897
09-13 00:03:54.137: V/GameActivity(23389): Last angle is 360.0
09-13 00:03:54.137: V/GameActivity(23389): Rotation will be -359.5724274931666
09-13 00:03:54.137: V/GameActivity(23389): ****************

while(Math.Abs(angle - lastAngle) > 180)
    angle += (angle > lastAngle ? -360 : 360);