[yookd]

Like Devan stated below - "We position ourselves between Gumroad & Shopify (if they did payments)".

In the future, we plan on adding widgets that will work within our application that will cater to some of the cases you pointed out. Some of these widgets will include date/time charging (tutor offering hours/days of work) and subscription based charging (SaaS service you mentioned). Of course, we're not limited to just that.

As for the PSD, we host the file for you so all you need to do is upload the PSD and after the checkout process, the buyer can immediately download it.