Hello! I'm giving a very short tutorial on how to make an icone square (since I often saw many un-square icons). toi don't need Photoshop ou GIMP ou heavy picture editors. Here I'm using link
1. Click "Editor". Here you'll see a Photoshop-like layout.
2. Click "Open image from computer". Select your icone ou any picture toi want to make square.
3. Click on the "Crop" icone on the haut, retour au début left of the panel. Choose "output size" on the "Constraint" dropdown. Enter 200 x 200 ou whatever square size toi want.
4. Drag the souris over your picture. Hit Enter.
5. Don't forget to save your square picture!