I have a cheap torch (US: flashlight) which has three AAA cells in series powering nine white LEDs in parallel, nothing else that I can see. I guess the current is limited by the battery impedance.
One LED is off, four are on, three flashing at about 15Hz and one flashes every few seconds.
I suppose when on, the current draw is sufficient to drop the battery voltage, the three LEDs go off and the battery recovers.
Good enough for a US patent anyway.
Cheers