+ Sign Next To App

[BigOrangeSU]

What does it mean when there is a plus (+) sign next to the app in the app store? I know in the itunes Music store it means DRM free because it is itunes plus but what about in the app store? There has to be DRM on the all the apps. For me there is a plus sign next to the following (In addition to others, just a few I am noticing):
Farm Story
iBooks
Pandora Radio
Solitare

 

[GoCubsGo]

Means the app is universal. (ipad & iPhone).

 

[BigOrangeSU]

ya good catch. I never use the app store on itunes so I would have never seen that.

thanks!