I plan to buy either Mac or Mini Mac soon. My question is: If I log into my friend's iPad or Mac to make a few purchases - how will this affect our accounts? Since the logging in information will be on my friend's iPad or MAC. For example, if I log in, will he get these Apps that I purchased so far on my iPhone for free? The same thing goes for making any purchases on iTunes, iPad or iPhone Store? Please let me know. Thank you. Sorry if I am asking wrong questions in off-topic threads.