Coloring apps are super popular, and if you need proof, check the App Store. There you will find that, currently, two of the top 10 free apps are for coloring – and experts say they aren’t just for kids, claiming they can help reduce stress. PC Mike Wendland tells you this week about three of the highest charting.  Color By Number currently is number two on the list of top 200 free apps in the App Store. The app features family-friendly content from a variety of fun images, from doughnuts and flowers to unicorns and hearts. The app is free for iOS with premium features available for purchase. The…