Changing Aspect Ratio of Featured Images

I use Etsy and their preferred aspect ratio is 5:4. I cannot spend hours and hours resizing and recropping and reprocessing photos. I have searched this form high and low and cannot find a good method of changing the featured image aspect ratio. Do I have to pay to get this information? I have tried the simple image sizer and it did nothing as far as I can tell. So, did someone figure this out or how much money do I have to throw at this issue to solve it? I love Kale but I need aspect ratio consistency.

The page I need help with: [log in to see the link]