Looks like Scholar Turbo has GPT-4 and Chatpdf is still on the waitlist. But yeah, these chat-with-your-doc webapps are popping up out of the woodwork.

For fun, I whipped a quick one using our platform at https://trypromptly.com/app/65573e71-c05b-4567-87e8-49688c82.... (Initial chunking of PDF takes a bit of time because of rate limits with my account)

Also https://pdf.ai