Read more: http://www.computeractive.co.uk/2202902
Just like any other software on your computer, it's important to keep Windows 8 apps up to date. You can see here that there is a number on the Store tile and this is alerting us that there are seven apps with updates available. Click or tap on the Store tile.
Click on Updates at the top to see a list of apps that should be updated. Hopefully they should all be selected by default. If not, click on the Select all button at the bottom left. When you're happy with the selection, click on the Install.