Need Experienced Someone to Build a Browser Based Interactive Worksheet system

YOUR BID PRICE IS FINAL## NO LATER CHANGE IS ALLOWED## I DON'T DEAL OUTSIDE FREELANCER## PLEASE WATCH THE ATTACHED VIDEO FIRST I need an experienced programmer who can build me an interactive worksheet system where users can register/login and then can upload files of docx, PDF, JPEG, PNG system to make interactive worksheets as per the attached video. Features like adding image, short answer/long answer box/drop down/radio/adding image, hyperlink, audio, video, comments in particular place, preview etc to be there. It should also have auto-checking and scoring system and sharing in Soc ial media system as well as email sending system and should be able to embed worksheet as iframe. Each worksheet created should have unique URL for sharing. I need full source code, co pyr i g ht and installation in my shared linux server. Code should be well commented and clean. I need regular updates. Lowest Bidder will Win.