Whenever youre ready, Virgin Mobile and Walmart want to make the process as pain-free as possible with wireless plans and parental controls you can change on the fly — right from your smartphone. Mom and Dad wont even need to be on Virgin Mobile themselves to make adjustments. A new product from Sprints prepaid division, Virgin Mobile Custom plans go on sale Aug. 9 at more than 1,800 Walmart stores and start at as little as $6.98 per month (for 20 text and 20 voice minutes).