What app can I use to cut a part out of one photo and put it in another photo?

I'd like to cut a part out of a photo and add it into another.ex i want to cut a daisy out of a picture and add it into a photo of a field. Anyone know any iphone apps that could help me

I know there's a new catch phrase around: "There's an app for that", but guess what… Not EVERYTHING is done via apps.

Sometimes, we still need to learn how to do something and need to make an effort to get to the result.
Other times, there really IS an app for it, but doing it yourself the "hard" way gives far superior results.

For a project like that, you need an image "editing" program.
Adobe Photoshop, PS Elements, PaintShopPro, Gimp or even Photoscape (the last two are free).

Using a website is fine if you only want to do a few photos, but resident programs are the much better option if you have more or want to do this regularly. If it MUST be a free website, try http://pixlr.com/ or http://www.sumopaint.com/ or http://aviary.com/.

Be prepared that you'll have a learning curve ahead of you - such skills don't just simply happen, they require some EFFORT on your part.