Graphic.ly is a late entry to the iPad digital comics race, but they are doing their best to catch up. This week, they are offering the first issue of Mouse Guard: Winter 1152 for free, which is pretty sweet. It's not a new comic — it came out in 2007 — but the single issues are hard to find now, and it's a very nice read.
While it works a bit differently than comiXology and Comics+, Graphic.ly is an interesting choice if you're interested in alternative comics. They carry Marvel and Archie, sure, but their publisher list also includes a lot of little-known indy and self-published comics. This makes for a lot of variation in quality, frankly, but there are also some gems: If you want to read Caryn A. Tate's Red Plains: Range War (illustrated by Noel Tuazon, the artist for Tumor and The Broadcast), it's there for free. And Graphic.ly seems to be the only iPad app that carries comics by Archaia, the publisher of Mouse Guard and the Fraggle Rock comics. If you're interested in the long tail of comics, Graphic.ly is not a bad place to start.
Like most comics apps, Graphic.ly is not restricted to the iPhone and iPad; they have versions available for Adobe Air and Windows 7. (I talked to CEO Micah Baldwin about the app last September.)