Too Long; Didn't Read
Readwise is a subscription service that helps you to remember what you’ve read using proven techniques. It syncs all your highlights and notes from your Amazon account, Instapaper, etc. It uses a mix of techniques like Spaced Repetition and Active Recall to master the knowledge you have acquired. My favourite features of Readwise are the Mastery and daily highlights using spaced repetition and active recalling. Readwise has a native tagging feature for organising your highlights spread across multiple topics. It also has an inline tagging feature that allows users to create tags while using Kindle.