Testing an Addin integrated with web based application

We developed an Addin integrated with MS PowerPoint and this addin to be used by a trainer (the user) who first must buy the license and try the features including MCQs, Rating, scale, wordcloud, grouping features. the Addin is to be used by trainers and trainees who can vote when the questions comes out in front of them. we have a simple mobile app and simple trainee website (audience website) where they can enter a code only to be able to vote.
Testing an MS PowerPoint Addin integrated with Admin, Audience (User) interface & mobile App
Testing as functionality & errors, bugs, speed, tolerance, fields,
All to be presented as screenshots & full Report identifying the Problems , risks ,errors, solution, ....