I'm working on Polar: https://getpolarized.io/ https://getpolarized.io/ It's been out for about 1.2 years now and we're really starting to nail some important

I'm working on Polar: https://getpolarized.io/ https://getpolarized.io/ It's been out for about 1.2 years now and we're really starting to nail some important features. JUST about to post a new release now. COVID19 is having us pivot a bit in that we're going to experiment with collaborative group reading in the hopes that students can work more efficiently with their colleagues without having to leave home. The core idea is to have a fully-integrated reading platform sort of like an integrated development environment but for non-fiction material (textbooks, research papers, documentation, plus web content). Right now we support PDF and web content but are actively working on EPUB and improved reading of web content. The key functionality is built around annotating your documents and taking notes and building flashcards so you can maintain a personal knowledge repository. It's also Open Source and supports cloud sync. We have a mobile webapp now and working on porting it over to Android soon.