Teachers should be able to create an "assessment" where they simply upload the pdf of their test. Then students complete their individual version of the test right in the schoology app. Think like the grading view for teachers on the IOS app. Teachers are able to access drawing tools and write directly on the student's pdf submission within the schoology app! Recreate that view for students. The students would open the pdf directly in schoology, complete it using the same drawing tools, and then click "submit" when finished.
Also important in this feature would be a time limit that auto-submits when the students finish.
Schoology is lacking in any sort of way to provide free response assessments for math or science where calculations need to be demonstrated. All of the features I laid out above already exist in some capacity within schoology, so it's simply a matter of taking those and combining them into a relatively simple tool!
Final important feature would be having access to the same grading tools for an assignment (markups, comments, scores, audio, video, etc.)