This app allows you to run apps on your phone (experimentally) and 7" tablet as if you have 10" tablet!

No more YouTube without related videos, no more phone-ish Play Store. All you have to do is tap the application shortcut. The display settings will be reverted as soon as the application is closed or hidden. Enjoy!

Also, unlike with all those DPI changers and switchers (such as LCD Density Modder that soft-bricks Jelly Bean devices), no root is required on Android 4.2 (but on 4.3 it is) and no brick can happen. If you experience any issues, just reboot your device and you are good to go.