Key Levels [@treypeng]

Draws horizontal lines for Daily, Hourly (1) and Weekly levels. Really handy to switch on quickly when scalping.

Light blue: Previous hour OHLC
Thick light blue: Previous hour Close / current hour Open

Dark blue: Yesterday OHLC
Thick dark blue: Yesterday Close / today Open

Purple: Weekly Open

It's a bit ugly, I'd prefer horizontal rays instead of lines stretching back across the chart but I couldn't figure out how to do this in PineScript. If I get it sorted, I'll publish an update.