The iTunes store has long had a free song of the week and some of the developers have offered their an app or apps periodically, practically from the beginning of the App Store. Besides the Free App, there is a selection of Editor’s Choice Apps.
The Free one for the iOS Store is Cut the Rope: Experiments. I haven’t been able to find one for the Mac. Hopefully this is just the beginning of being able to find useful apps in the store.
Another way to do that on the Mac is a section that shows apps that use iCloud to keep their data synced. At this time, those are iPhoto and Aperture from Apple plus the following:
|Galaxy on Fire 2||(Game)|
|Due||(Productivity – Reminders)|
|Day One||(Lifestyle – Journal)|
|djay||(Music – DJ System)|
|iA Writer||(Productivity – Text Writer)|
|SketchBook Pro||(Graphics & Design – Paint & Draw)|
|Byword||(Productivity – Markup Text)|
|ToDo||(Productivity – Task Manager)|
|Wikibot||(Reference – Wikipedia Reader)|
|PDFpenPro for Mac||(Productivity – PDF)|
|Screens VNC||(Utilities – Access Mac)|
|Reflow||(Music – Music Notation)|