We use Meteor because we were trying to find a really good framework for Node.js. We were originally building our applications with PHP and Symfony but decided to switch over to Node. We needed a framework that can be just as suiting as Symfony was.
Our team relies on Slack for communication and project management. Our team is based out of our HQ but we have sales people in Seattle, the Bay Area, and Amsterdam so it helps us communicate across the globe.
We use Heroku because it offers a wide-spread of features that our studios love. We are able to deploy applications for our clients and send them out for testing, add in great addons, and even run domains on the platform.