I was wondering if there’s any plugin + service that would allow me to create an in-app purchase of content on both Windows and Mac platforms?
I’m not aware of an ‘out of the box’ solution for this (there’s one for android that I’m aware of, but not PC/Mac)- but there may be something lurking in some dark corner of the Asset Store if you check there.
I would imagine that it isn’t all that hard to roll your own once you start breaking down the components. for example- if you’re using Unity Pro, you could use libCurl to connect to just about any payment gateway (such as paypal) to verify transaction details. You’d need to parse the XML response from the payment gateway to find out if it was successful- and if so, release/unlock the content. You may or may not need some sort of SSL-enabled middle man for the transaction- that all depends on whoever you’re using for payment processing and what their requirements are.