Video streaming and uploading. I suspect we'll see a lot more people running livestreams outside their home/office, like in various tourist destinations or on the daily commute. YouTubers will also probably like being able to post videos more easily when out and about too.
Based on this, I also think it's likely streaming video may become more of a centrepiece for mobile apps and what not than it is today. Imagine having a news reporting app that lets people at the scene of an incident/event report the news like they're on network TV. Could be quite the boon to citizen journalism.
Might also help remote working become viable for more people as well. The old digital nomad lifestyle wasn't too practical without wifi before, but now working anywhere could be a lot more literal.