^ like that first line.
Yes, a brake is featured on those I've been looking at. Could never consider ANY mode of transport that didn't have a brake!
The better equipped ones have the flip-flop Hub, to switch from permanently fixed, where the pedals spin permanently, to free-wheel - where you can coast along and the pedals stop spinning when you do. The latter for a Fixie novice sounds safer, although the pro's will say fixed, so they force the pedals to stop and skid the rear wheel to slow down......
Am interested in these because of their simplicity, price, VERY light, plus they promote excellent spinning skills, which is a great technique to master for riding long distance, on geared bikes. My colleague also said not good for LONG distance, best on flatter routes, with limited hills.....
London plus Cities you can understand how these have become popular. Alot of Stop-Start traffic, mostly flat terrain, nimble, plus as Bretty states, less to get stolen off it too!