The are quite a couple of icons that you can set, though not all of them are absolutely required.
For the tile we have the following logo sizes. I also created the example of an app I’m working on.
The main tile requires a logo of 150x150 pixels.
Then we have a wide logo that’s only required when you want your app to be visible with a wide logo on the Start screen. When you use it, the size has 310x150 pixels. That’s two tile logo’s + a 10 pixel margin.
Then we have a small logo that’s used in all kinds of views inside Windows like search, share and more. It has to be 30x30 pixels.
Next we have a badge logo. This is logo that can be shown on the lockscreen when there are notifications from the app, and as of this it’s only required if you want to enable showing your badge on the lockscreen. It has to be a monochromatic logo of 24x24 pixels.
We shouldn’t forget the splashscreen, it isn’t really a logo, but often does contain the logo. Besides there are constraints about size here as well, being 620x300 pixels.
And in the end the Store logo is what’s left. Interestingly this is something you configure as part of your App package, though it’s on the Packaging tab while the rest is on the Application UI tab. From Windows Phone we are used to supply this icon during submission. This icon has to be 50x50 pixels.
I’m sure you can come up with more creative icons, but I hope you now have an understanding of all the icons that you have to create.