I've bought two ebooks from there for $5 each and I think they are worth it. You can read them online you can make bookmarks and also it preserves your reading

I've bought two ebooks from there for $5 each and I think they are worth it. You can read them online you can make bookmarks and also it preserves your reading progress or you can download a .pdf / .epub. I haven't found a better / cheaper resource for learning new technologies. P.S. The books I bought were for Golang and VueJS.