One thing I, as a physics teacher, I have a dislike for most web-based projectile simulations. Many are just simple graphs. Some, like the PhET simulation do try to make things semi-realistic. However, even the PhET simulation has limitations. So I decided to make my own. See it at
The Computation Layer tools used in it include
randomly generated values for initial angle, initial height, and initial speed
student entries for their predictions are transfered to later screens so that they cannot go back and “postdict”.