My background: 15 year, highly effective 6th grade public school math teacher in a very demanding Long Island, NY school district. I have used Proprofs now for 4 years and without a doubt still call it the very best software a teacher could implement to raise their student's level of any subject. Proprofs to me is like how the Smartboard revolutioned classrooms. If you give a weak teacher a smartboard, you do not see much productivity, but give the board or software to a creative, innovative hard working educator and you see results that are above anything.
The features are so customizable; they have covered anything that any teacher could ever need or want. Proprofs as a company is the most responsive and open to their customers as far as communication and feedback while always looking to improve.
I am not going to list everything it can do, but let's just say this. Anything you could ever need or think of, Proprofs is ready to handle. At times there may be some small issues, but this is every company. They fix things right away.
I believe what started out as a quiz maker has really developed into having students learn from the assignments; not just about questions and a grade. They are in their own niche and no one is close to what they do.
I have been so happy and every administrator or teacher I show it to, cannot believe the power of me knowing when my students did their hw, how much time spent on each question, what their % was, the ability to let them redo it to reach a target, email scores to parents if needed, ability to implement graphics in questions and answers, video responses, ability for students to see and learn from full explanations, notification every time a student finishes his/her work, open ended questions with the ability to score their answers like essays (no one has this) and much much more.
While other companies say "we can't do that in our program," over the 4 years Proprofs always says "Yes we can or we will figure out how to implement it."
Go look for another company that does what Proprofs does; you'll never find it.