Years ago I saw a flashlight (torch?) that used the LM3909 IC. It was originally a 2-cell flashlight, but they removed one cell and replaced it with the LM3909 blinker/battery-voltage-boosting IC and an LED. The blinking LED was so you could find the flashlight in the dark. With only one cell, the flashlight wasn't very powerful since the LM3909 couldn't double the voltage for the lightbulb.
Google LM3909 and you will find some circuits that use a few transistors to replace the LM3909. :lol: