What 3rd Party SMS service do folks use for sending mass / bulk texts to their clients?

Hey Kyle, we've been using the Notify Customers app. It works great and affordable. You can use tags to organize who you send it to, and it also syncs with jobber. We haven't really used email since, just because of how effective text alerts are. This was a no brainer for our business and I always find myself recommending it. 

Here's the link: https://secure.getjobber.com/marketplace/notifycustomers