ShareTo:Resize

ShareTo:Resize is a unique image resize utility. On top of what you would expect (run the app, pick images, resize), the app also knows how to use Windows 8's sharing capabilities to get and reshare resized files.

That means that you can go to any app that can share out images, select the share charm, pick ShareTo:Resize and use the share panel to resize your images. Once the resizing is done, you can click on the "Save to folder" or "Reshare" to take the newly resized images and save them or take them back to another application.