Hello!
I'm interesting your project very well.
I'm a Good expert of PHP, Node.JS, Angular.JS, Java, CSS, HTML, HTML5, Javascript, Website Design, Mathmatics, Algorithm.
This is the answer you asked.
The major difference what you see is that COM addins will be running in the user device or in the Office Client. The new Office Add-ins don't involve code that runs on the user's device or in the Office client.
I m quite well experienced in these jobs.
Let's go ahead with me
I want to service for you continously.
Thanks