Hacker News Reader

If you occasionally need Adobe Reader/Acrobat exclusive features but don't want to install, you can use the free online version of Acrobat. It's pretty decent though it doesn't have all the features:

https://acrobat.adobe.com/us/en/

I recently had issues with macOS‘ Preview.app and formulas. It’s a nice feature, but probably not widely supported.

Whoa, I had no idea PDFs can have formulas.

You can embed Javascript in PDFs

https://news.ycombinator.com/item?id=38768892