The Apple Watch is a very powerful wrist-mounted personal communications device, but with that great power comes great responsibility for battery life.
Whilst the internal HRM is satisfactory for some activities (sleep,
Both Garmin and Polar make chest strap heart-rate monitors. Garmin's product looks expensive, but you only ever need to buy one: it'll fail within the warranty period and
I think William Gibson is best known for the Sprawl trilogy, and specifically Neuromancer. Amazingly he has written other books: the Blue Ant/Bigende trilogy, and the Jackpot series, among others.
Pattern Recognition