Thought it'd be appropriate to plug what we're working on here. We're a YC company (W19) are building an iOS browser that's extensible. You can build "extensions" to inject your own JS into pages if they match a certain condition.

We're still beta testing (and launching early next year) but you can get the browser testflight beta from here https://insightbrowser.com/ and the AMP disabling extension here http://share.insightbrowser.com/8

Would love feedback or any changes you'd like to make. Feel free to respond here or abhinav@insightbrowser.com

Will this pass Apple’s review? I thought anything that allowed you to run arbitrary code on their platform was an automatic hard no.

I run a Chrome extension that's popular here on HN, called BeeLine Reader. We have an iOS app (and share/action extensions) and have toyed with the idea of building a general-purpose web browser, but we'd much rather be part of an extensible mobile browser. Would love to chat about how you're attacking this problem (and avoiding related App Store prohibitions)!

Nice I'll take a look!