The New York Times Bits Blog reports that blogging platform Medium will unveil an iPhone app this week, its first mobile app since launching in 2012. The app is said to be strictly for reading Medium posts — not yet for writing — which would jibe with Mediums focus on longer-form, high-quality content not well suited for composition on a phone. Mediums site already works very well on a mobile browser, so the open question is how the app will differentiate itself and what additional features it might offer over a simple bookmark. Mediums first app comes weeks after founder (and Twitter board member) Ev Williams raised a $25 million round for the company that was earmarked for a new San Francisco office, hires, and infrastructure.