Using a CMOS 555 timer, you can drive seven high-brightness LEDs from a single 1.25V cell. Analog switch converts 555 timer into pulse-width modulator Added CMOS switch enhances a PWM oscillator. Use ...

This is a pulse generator with adjustable duty cycle made with the 555 timer IC. The circuit is an astable multivibrator with a 50% pulse duty cycle. The difference from the standard design of a 555 ...

With a little work, you could probably adapt this idea to any number of circuits out of the 555 playbook, like a PWM generator, for example. There’s almost nothing a 555 can’t do.