How to download paid apps for free on AppStore iPhone?

Is there any way to download paid apps for free from AppStore? I have an iPhone, and iPad, so basically the same thing. Legally, too, if possible?

Easy - you become a petty thief. But why stop with apps? Why not knock over the local 7-11?

Actually, there's a legal way to do so…
On your iDevice, navigate to the following website:
http://m.freemyapps.com/share/email/ef0ee82a

This is basically an app-sponsoring website that gets money from advertising for these apps, and shares a portion of it's revenues with the users (us).

Once the link above is opened, click on "Get Started."
Then it will prompt you to install something, that will be you device's profile. This is used to check with the websites server that you have downloaded their sponsored apps, then reward you with certain credit.
After you have successfully installed your profile, go back to Safari, and navigate back to the original page of the website, and click refresh.
You should then be able to see a list of their sponsored apps (mainly games).
Click on one of them to download it. The website will navigate you to the AppStore to download its free-sponsored-apps.
Once you download one of these apps, MAKE SURE to open it for some time- around one minute.
When done so, go back to safari, to original page, refresh, and you should notice that you have been rewarded with some credit (according tot he game you have downloaded) on the very top right corner!

Keep doing the same thing with the rest of the website's sponsored apps to collect more credits!

What to do with those credits?
Check the "Gifts" section in the website. It lists down its different rewards, and for how many credits you get redeem each reward. These rewards include iTunes credit, hulu registration, and even amazon cash!