If headsets like Glass are pushing the wearable computing boundaries, then fitness monitors like the new Fitbit Flex are entry-level cyborg tech for the mass market. Announced back at CES 2013, and taking on Nike's stylish Fuelband and Jawbone's twice-refined UP, the Flex promises to track your performance whether you're awake or asleep, along with real-time data transfer to your smartphone without a big hit on battery life. That's even though the Flex is cheaper than UP, falling just under that all-important $100 boundary. Is this the health tracker we've been waiting for? Read on for the full SlashGear review.