Instapaper’s new(ish) InstaRank feature on iOS is really helpful for picking out what to read next. It lets me find what’s popular now from among the articles in my reading list and lets me filter my list based on the amount of time I have to read.

One of our ambitions since taking on Instapaper has been to build useful ways to make the reading experience more productive. To us, that means making it easy to find the best article to read (or video to view) for the moment you’re in. To that end, we’ve added a bunch of sorting and filtering capabilities into the new iOS 7 app for iPhones. (They’ll show up in the very near future on our iPad and Android apps, and in the web interface.)

Mobile first used to mean designing for mobile and then stretching the interface and underlying app to fit a bigger screen. FiftyThree’s Pencil stylus made mobile first about adding specialized hardware to compliment a mobile app.