I recently purchased a Iphone 5 in turkey, and when i try to log in into the app store is asking me for a credit or debit card. How do I by-pass this? Why I get asked for such info? Thank you.
In the settings for your Apple ID there is a payment options selection, where you can chose none. You can find this in the menu called Settings in your iPhone. You may also have to check the settings under iCloud.
There is a really super answer here, check it out for lots of details, even pictures; this is for the most part, the same on the latest versions.
I understand, you want to just get free "apps!"
If you might also want to pay for things sometime, another really nice option, is that you can go to almost every kind of shop (even a convenience store) and buy an iTunes gift card with cash, which will come with instructions about how to add this credit into your iTunes (and therefore also automatically your "App Store") account.