[slowkow]

I use diigo. The free version lets you cache the page, annotate the page with highlights, and tag your bookmarks. The extension for Chrome works very well. They also launched some PDF annotation features, but I haven't tried that.

https://www.diigo.com/

[vinay427]

Unfortunately it appears that the free version does not include page caching, according to this table: https://www.diigo.com/premium