I’d never use a case, but when they-fix-I-buy the iPhone 4, I’d either get a replacement wooden back or this leather skin. Not only it will protect its very fragile back but it’ll give it the classic Leica look:
https://gizmodo.com/apple-will-give-free-bumpers-to-iphone-4-owners-5589004
Kind of. The Deep Black skin is $20, which is kind of too expensive considering it’s not real leather. [SGP Store via Unplggd]