Scaling a photo for iPhone wallpaper?

I know it can be done. I have the perfect picture that if it would fit correctly on the screen, it would look good. Is there a free app I can use to make it fit my screen? Or what should I do?

Why do iphones lose value so fast?

Why do iphones lose value so fast? - 1

Added (1). for example 8GB 3G version is around $15 through ebay now. When it come out it was $200 upfront plus monthly at least $60 for contract 2 yrs so $1440 for service add $200 for phone so nearly $1700 and now it cost $15.

Is it possible to update iPhone 5 from 7.0 to 7.1.2?

My dad decided to make the plunge from flip phones to a smart phone. As he is extremely clumsy I thought a good compromise would be to give him an iPhone 5 I have laying around. It currently has ios 7.0 on it. I think he'd appreciate performance over extra features he'll never use, so I'd like to keep it on ios 7, but upgrade to the newest version of 7.1.2. Is it possible? I know the only version currently being offered is ios 9 officially, though doing an OTA update offers an update to 8.4.1

Added (1). If not possible, should I stick to 7.0 or go for 8.4.1? I've read it's far more sluggish a phone on ios 8.