The best pieces of technology do exactly what they need to without getting in the way. Sadly, the only gadget I own that can make that claim isn’t my smartphone, or laptop — it’s my bloody smart bathroom scale. I bought a Withings WiFi Body Scale back in 2011, and since then, it’s done nothing but reliably record my weight for four years. The thing about “smart” devices, though, is their smarts tend to come at a cost. Sometimes battery life is sacrificed, the experience is complicated, or form…