“I want to email an iPhone screenshot to a friend. Is there a free app for taking iPhone screenshots I can email?”
You don’t need an app to take an iPhone screenshot. Apple built the ability to take an iPhone screenshot into iOS starting with version 2.0. To Take an iPhone screenshot, all you need to do is hold down the home button, then press the sleep/wake button at the same time. This should make your iPhone screen flash white and a camera snap sound effect play through your speakers.
Once you have the iPhone screenshot, emailing is as simple as attaching the image to an email. Open your mail on your iPhone, compose a message, then add an attachment. You can choose the iPhone screenshot from the available iPhone photos. Pick the size you want and send the email message.