Many power brushes have timers and this can help you brush the recommended two minutes. Brushing is not enough; you also need to clean inbetween teeth to thorougly remove plaque. Dental floss is the most recommended product by dental professional, but it requires a high level of dexterity and can be hard to do for many people.
Sprint offers roaming on Verizon and partner networks. This costs us money. Boost work only on the Sprint native network, with no roaming. This saves us money. Thus, Boost is somewhat less expensive than Sprint.
Right, there is no phone you can use both on Boost and also on a GSM network. (There is a phone called the Nexus 5 which is carrier unlocked and has both CDMA and GSM radios but it is not accepted by Boost for use on Boost).