Some web pages have the Save image As... option disabled on a right click when you try to save an image. Let me show you how to get that image anyway using Firefox.
If you are on a certain data plan on your mobile provider, and don't want to exceed it, you can set data usage warning and a limit which can help you save some of your money.
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.
Cool thing about Google Drive is you can access all your documents from anywhere and you can actually upload a Microsoft PowerPoint presentation which automatically turns into Google Drive Slide.