The last time i connected my iPhone 5 to my laptop and synchronized with iTunes, something weird happened. All of my paid applications keeps asking for my Apple ID and password and entering just closes the application, and if i tried to open an application without internet connection, the app just closes instantly like a crash. i tried to restore but no good. One important note is that the apps were downloaded by a friend of mine using his account, then i made an apple account but i didn't enter my credit card information so i can't buy application using my account. so i am just wondering if this is the problem, the apps were paid by different account and my account doesn't allow purchases, or what do you think ?
You say the apps were downloaded under your friend's account, and they are paid.
Paid = You pay for it -- not friend pays for it.
There is a limitation in iOS preventing this from happening - you will need to know your friend's Apple ID and password to open the app - to prove it was you who bought them.
Without this limitation, there would be an epidemic of groups of college students using one Apple ID to 'split' the cost of apps, and have them on a lot of different people's devices. This is stealing from both the developer and Apple (Devs get 70% of app sales, Apple gets 30%), and Apple doesn't like to have it's cash stolen. Devs don't either. I'm one of them.