SendOwl

If you are looking for an incredible platform for delivery of your digital products your search stops here. This is by far the best on shopify especially if you have many digital products. Other apps force you to upload the files to their servers whereas sendowl lets you host the files on your own server. This will save you a lot of money since you would otherwise be forced to pay a premium for the storage space. Their customer service is the top notch. I reported a bug and they fixed it within a day!