You don't need Photoshop or some other advanced piece of software to resize a large number of images at once. You can use Microsoft Office Picture Manager which is part of the Office suite.
Knowing how to select parts of your Gimp documents with the help of Quick Mask might be one of the first things you should learn when starting with Gimp. Let me introduce you to the basics of Quick Mask.
If you want your progress bar to look a bit different you can create it in a shape of a circle with counter in the middle. We will create in a so called flat design trend using Adobe Photoshop.
