Kobo (eBook store and readers)★★★★☆A solid alternative to Kindle, from the eBook selection through apps and hardware. The app works well on my eink tablet without too much tweaking, though it still wants to sell me more books before I can open the one I want to read.
Pocket (discontinued)★★★½☆I used Pocket for ages to better manage my time reading articles. Eventually I soured on the way it’s turned into a recommendation engine. And now Mozilla’s discontinuing it. Wallabag is a decent alternative for the read-it-later aspect.
Wallabag★★★★☆A read-it-later type service built on open-source software that you can run yourself if you want (but don’t have to). Not as polished as Pocket, but it’s sticking around, and you know it’s not using your saved bookmarks to train a recommendation engine.