I was dubious about using an in-app Paypal upgrade, but figured even if Kev is doing anything dodgy my 2 factor auth would protect me...

But I can't complete the purchase because of my 2 factor auth.

Is there any way I can purchase the app without disabling my 2 factor auth? If not, sorry but I won't be buying.
Totally understandable that you don't want to disable 2-factor auth. I am using the official Paypal Android SDK, and it doesn't appear to support 2-factor auth. I will see if there are updated libraries though from Paypal, maybe they fixed this in a new release.
Beta version PayPal looks slightly different, and gives a more easily understood error, but still can't buy :(

This is a screenshot of the two factor auth error I now receive.
PP-error.png (24.91 KiB) Viewed 2880 times
Heh, oh Paypal. At least they give you a message now. :p

Sorry man, there isn't anything else I can do. This is in PP's hands =(
Hmm ok. Though I'd have thought this would make you more keen for an out of app purchase option? :)

Have to say, very impressed with the speed of your response. However I'm not about to take the risk of disabling two factor auth, or entering my CC details directly into an app.

Any chance you can make use of Google Wallet for checkout?
I'll look into an out of app model, but it would be doing the same thing that the app currently does. An out of app model would redirect you to Paypal's site for purchase. The app does the same thing, but instead of a site, it's the Paypal's "app." When you click "Upgrade to PRO," the app launches the Paypal SDK and exists nzb360. So technically, an out of app model would be identical to the current setup from a security perspective.

Since Google originally pulled the app, I would prefer to not use GW.

I am reaching out to PP to see when they are adding 2-factor auth support in their SDK. I had to work with them on the Android SDK before to get them to support CC's on Android. They're a bit slow to adopt their own features, heh.