If you own a smartphone or tablet, you should be using Mobile Nations. Mobile Nations is a group of web sites that each focus on a mobile operating systems. Each site has app reviews, hardware reviews, accessory reviews, tips, resources, forums, help topics, and much more.
These sites are great for anyone who uses a mobile system, including teachers, students, and others. Find out about new apps, resources, tips, problems, help and more. Share them with your friends, students, and colleagues. Education apps and uses for the systems are often featured on the sites. EdTech and IT personnel can find help information, reviews, and more to help them use these devices.
I use Android Central (and subscribe via RSS) for my Android Smartphone to find tips, app reviews, and more. I've learned about new apps, problems, help tips, and more from these sites and spent a lot of time on Android Central reading phone reviews before purchasing my HTC One Android Smartphone.
There are 4 sites/communities based on different mobile systems.
Crackberry for Blackberry.
iMore for iOS (iPhone and iPad)
Windows Phone Central for Windows Phone/Mobile