Why would a extension that has a paid upgrade option potentially contact a provider of services to implement paid upgrades in browser extensions, mysterious indeed. A question requiring many, many question marks.

The extension uses ExtensionPay [1] to accept payments via Stripe for the Pro upgrade. It's open source and created by HN user Glench [2].

[1] https://github.com/glench/ExtPay

[2] https://news.ycombinator.com/user?id=glench

But Google Chrome has the following note in the extension details view after you install it:

> This extension is not trusted by Enhanced Safe Browsing. Learn more[1]

[1]: https://support.google.com/chrome_webstore/answer/2664769?vi...

Hmm, this seems to be because of Google's new policy for verifying extensions. The domain (modernhn.com) hasn't been used for an extension before, so it needs to be around for a few months with a good track record to be verified. Their page [1] says:

> For new developers, it will take at least a few months of respecting these conditions to qualify.

Modern for Wikipedia [2] already meets those standards, and has the relevant badges, so I guess it'll just take some time for those to be approved and for the "Enhanced Safe Browsing" warning to be removed.

[1] https://developer.chrome.com/docs/webstore/discovery/#publis...

[2] https://chrome.google.com/webstore/detail/modern-for-wikiped...

If you read the site, there is an option to pay for premium features. I would assume that extensionpay is a vendor that helps with facilitating those payments.