Show HN: Better reading retention via spaced repetition of your highlights

Hey HN, happy, but also a bit nervous, to be launching 1.0 of our reading product: Readwise.

We were first on HN about a year ago, when Readwise was a simple tool to organize Kindle highlights. Since then, we've completely overhauled Readwise into a full product which uses the power of spaced repetition to help you retain any type of book/article reading.

The way it works is fairly simple: we import all of your highlights (from Kindle, Instapaper, iBooks, Highly, etc.) and then carefully select a small batch of them each day to send to you. You easily review those highlights through email or our webapp, and the result is that you're constantly rereading (and thus better retaining) what you read.

There's obviously a lot more (tagging, search, recommendations, etc.) and we wrote a bit more about it all here:

https://www.producthunt.com/posts/readwise

Curious if HN has any feedback, or qs on how the technical side works!