Of course, there are some awesome tools out there to help you as a GM. This is an unordered collection, vote for your favourite ones in the replies below:

the infamous yxans klagan:

• https://yxans-klagan.vercel.app/

smoke raven has some really powerful tools collected, I'm especially amazed about this one:

• https://www.smokeraven.com/...

For the ultimate number-nerds:

• https://donjon.bin.sh/fantasy/demographics/

other Random generators:

• http://wyrmtales.net/?
• https://perchance.org/fl-session-generator

Onepage dungeon generator:

• https://watabou.itch.io/one-page-dungeon