You can "Spark'' specific cards of a Hack that you find interesting, inspirational or just want to remember. Once you Spark them, they’ll be saved to a Board in the Spark tab. If you are reading a Hack, you can Spark any paragraph, you just need to tap on it and the option to Spark will appear.
The idea is to create Boards around specific themes. You may decide to keep it simple - for example, having one Board for fitness, and another for history. Or you might pull from different categories to create something more personalized for you.
You can also use the Spark tab to revise these cards and boost your knowledge retention.