Is there a way to know if an app has been tablet optimized? I know the iPad has the "+" if it's universal.
I dont think there's a way other than looking at the screenshots and seeing if there's a tablet UI. While an unfortunate oversight, I dont think it matters as much on Android since phone apps scale far more gracefully than they do on the iPad (That is, no borders or pixelation).
Not much of an official way yet. This is a problem I have with the Market, both the lack of tab apps and a a way to identify before downloading. An application called Tablified Market exists, but it doesn't have the latest tablet apps as far as I know.
With searches I've done, I've found a handful of tablet apps that we're in the Market but not in Tablified Market.
Do you have examples? Ill gladly submit the apps to them myself. They have a submit button the site and within the app. Doesn't really get any easier than that.