How to set passwords for applications in iphone 5?

I want to be safe when someone uses my iphone. I'm okay with them using safari or playing games etc but I don't want them to read my messages, whatsapp, facebook etc. So I wanted to know about any way to set passwords for these apps without jailbreaking. Please even mention if they are free or not. I would prefer free ones.

Yes, go into the appstore and search "password folder" and you'll find a ton. The free ones are very basic by just making you type in a password, but some of the.99 cent ones give you a picture and if they don't identify the password it gives you the time and location. In my opinion, this is a great way to keep all of your personal info safe. Hope this helped.