I'm not an advanced user of pdfs so I'm not sure if there's anything major missing from these, but either Okular or just the built-in browser ones works well en

I'm not an advanced user of pdfs so I'm not sure if there's anything major missing from these, but either Okular or just the built-in browser ones works well enough for my basic needs of reading and the occasional form filling for the desktop, and on android I use muPdf.