We have used MailChimp and SendGrid in the past. We are currently testing Appboy; we are integrating it right now. It is the new up-and-coming tool to acquire customers and gain attribution: an all-in-one email marketing tool. We have not completed the transition yet, but it works very well for analytics and notifications.

We use AppBoy for all of our CRM campaigns. It lets us have a one-to-one relationship with our users, and to deliver to them the right message at the right time.

For app engagement tracking, we use Appboy; we have been using them since they formed as a company. It’s great and does everything that we need: push notifications, analytics, retention analysis etc.