SendOwl

*EDITED* (Went from 700$ plus a month to 150$ plus a month with the premium pricing plan : 99$ per month plus 0.11$ per transaction after talking with customer support) I have been using sendowl for 7 years and used it even before I got a Shopify store. The app works really well and have nothing to complain about the app really. I even struggle to find a replacement. However, in october they changed their pricing. I went from 20$ a month to 150+$ a month (on the new plan). Customer support was nice, responsive and friendly. However since this is their new way of billing (flat fee + transaction %), they cannot do more for me. I am pondering whether I will be switching apps soon because it's just too expensive.

Great app, simple to set-up, and get started with. Lots of options for digital content delivery, it was just what we were looking for.
We have had no issues with it, works great. The free trial give you enough time to try things out to see if it will work for you ... and it will.

My store consists entirely of downloadable digital content, and this app is perfect. Highly recommended if you need to provide downloads to your customers.

Update: Again, more kudos for this app, especially the customer service! I had some changes I needed to make (moving customers from one variant to another for several products) and they did everything for me quickly and with excellent communication throughout the process.