Your apps do not include a grading system where a website administrator write contents on his/her website, ask questions after for the reader to answer and display answers and grade after marking to the web user or student. Questions can be multi choice, matching, analysis, true/false, order, and fill in the blank. There should be question level of knowledge, age, skills, etc. There should be one or many teachers to mark a student and should be able to add in comments to students. After marking and grading a student should receive certificate of certification.