Get feedback, encouragement and inspire others.
A website and app where you can create a challenge like “read for one hour each day,” or “take a cold shower every morning.” Explain why you are challenging yourself to do this. Your personal reasons, and theory or science behind it, etc. During the challenge, you’ll update it regularly with your thoughts, pictures, videos, etc. Others can find and follow your and others’ challenges and give encouragement.
Making you prize and punishment (and the “what for”) public (even if you stay anonymous) might help you abide by it. Because it’s public, people can and will react and encourage you.
A site where you publish you goal, your carrot, and your stick. As time goes by you update your post with your progress, when you deserve your carrot, when your stick, and whether you actually received them. People can comment, encouraging you or criticizing you when appropriate, to help you achieve your goal.