I want to edit people's videos but need a way for customers to upload them.
Another service similar to the one mentioned is https://uploadcare.com/. Being restricted to SquareSpace means you need a widget that would be embeddable in their platform, that would come with this functionality.
You should also explore the big video players out there to see if they offer this type of widget (YouTube, Vimeo, Wistia, DailyMotion, etc).
