The chin up is a great way to build arm and upper body strength. It will strengthen your lats, back and shoulders. You can adapt your form in order to target and strengthen specific parts of your body.
Tip: Keeping the torso as straight as possible maximises biceps stimulation while minimizing back involvement.
Technique tip: Tense your glutes and grip the bar as tightly as you can when performing the exercise.
If you are struggling with chin ups or pull ups, then this article will be helpful: