The DC and Marvel apps were built for those companies by comiXology. Dark Horse designed its own app, which moves through a comic differently than the comiXology app (as well as organizes your collection differently, and so on).
As for the comic, I've been looking forward to this for quite a while. Several years back, I read the draft that this miniseries is based on, though I don't remember it very well at this point. I thought this first issue was a lot of fun, and didn't at all mind the political angles that so far seem to be better handled than the Prequel Trilogy handled similar ideas (though perhaps it's too early to compare). It's just really neat to see Lucas's early ideas fleshed out beyond a script, and to see the similar-but-just-a-little-off implementation of certain characters, vehicles (stardestroyers as two-man fighters!), and situations.