iPhone 3GS picture cropping? Is there a way?

[Soundless Voice]

Hi. As you may know, my computer crashed a year ago and I'm using my iPhone 3GS.

Anyways, I found images like this:

Spoiler: Slightly big

And I want to remove the background (Like for other models. That one doesn't really have one.)

I think there MIGHT be a picture cropping app in Photos which could work, but I can't remember where that is.

Any help is appreciated!

 

[User4042]

click edit

And then crop

And then adjust the rectangle

And click save

But you cant get transparency