If you’re a current Boost Mobile customer you can add 2GB of data to your plan for life by texting Boost2GB to 8005 from your Boost phone.
The terms are listed below:

Limited to customers with a minimum of 3 months of prior service on a qualifying monthly unlimited plan who have not switched plans in the past 90 days. Plan change will result in loss of eligibility for the extra 2GB of data. Text 8005 for program details and to check eligibility. Standard message & data rates apply. Eligible customers will receive additional 2GB of data after next month’s payment has been completed; additional data will remain for life of account if customer keeps account active and in good standing. Other terms: Video streaming limited to 3G speeds. After applicable data allotment reached, data speeds (including video) reduced to 2G speeds for remainder of plan cycle.