What kind of companies or teams will use a collaboration tool for remote teams?

The way I'd raise the question is not "what companies" but "what teams" or even "what personalities". Being continuously connected works great for smaller groups of extroverted people that are more common in startups or early-stage product companies that still have lots of planning to do. The other thing I would point out is your USP. The idea looks appealing on paper, but it is very niche. Think about why we have hundreds if not thousands of messaging apps and manyfold less dedicated software for calls. As Martin Cooper, the inventor of the first cellphone, puts it "I think texting ... for sending short communications, it’s very efficient. People do naturally tend toward becoming more efficient." Try to come up with what's the benefit of being always connected except for the "anxiety treatment", because I know many people who would rather become anxious or paranoid from the fact they're always on a call :) For your KSP I would definitely suggest mentioning your product doesn't require specifically high bandwidth. It's crucial for such all-in-one solutions to be extra reliable. My guess for your remote TA is art / creative teams, PM teams, or developers who practice pair-programming. Also, look, Millenials invented PTT :D