Just had an incident this month with a mobile application that consumed my whole months mobile data allowance. At the same time as talking with my network provider something prompted me to check my options with regard to tethering devices (Wi-Fi) wise to my phone. Maybe I’ve got a particularly shabby deal but evidently in spite of being a friends and family member of the big providers my contract doesn’t cover tethering. So double check your terms is my advice as you could be in for a nasty surprise.