I have Straight Talk for AT&T and use the unlimited text, talk, & data. Tether software on Android and computer is EasyTether. No trouble tethering using wifi but no tethering using 3G or 4G. Where wifi is present, I don't need to tether. I have tried 3 different smart phones, all with different versions of android from 2.4 to 4.1.2, with the same result. Also, I cannot activate mobile hotspot - "There is a temporary network problem that prevents the enablement of the Mobile Hotspot function. Please try again later." Seems to mean, never is going to work. EasyTether worked like a charm in the past on AT&T but stopped just before I switched to Straight Talk. However, was wondering if it would be worth the extra $15 to go back to a lesser plan for more money. I have read articles suggesting changing user agent string to articles suggesting vpn through HideMyAss. Any experience with tethering that works? If you have some specifics, I would really like to hear about it.