Here's what my youngest kid is doing for fun:

[James D Jarvis]

My middleschool-aged child is currently writing a desktop suite in Scratch. So far it's got a notepad program, a pong game, a bitmap icon maker as a paint program. He figured out how to be able to save larger files by having the app talk to another app which writes the actual files because Scratch seemingly only lets you save 10 variables in a browser cache otherwise as stored data. He is going to be adding an email or messenger applet to it as well and liked my suggestion of a calculator. He wrote his first computer game using gamemaker ( but using the GML scripting) when he was 6, I had to explain how variables worked in algebra and grid coordinates worked... once.  

The kid actually surprised me by explaining his workaround so he could write multiple and larger data files with Scratch. I just have to get him started with basic and C/C++ so he can start writing programs for me.

My wife and I will catch him staying up late or awake early watching videos on science, coding, and math.  

Other parents ask what he's into and I say computers and they think I mean "computer games", which he certainly enjoys but when I explain what he actually does they are surprised.  

At the same age I had played with my cousin's altair briefly and had only used a computer at the museum otherwise. It really is amazing how much children have access to today compared to when I was kid.

His birthday is coming up and I'm just a proud papa sharing this stuff.

[OldMoses]

I'm with ya. My son spends a lot of time on YouTube, but he's generally been using it in pursuit of "auto", as in auto-didactic automotive engineering. He's been a sort of "engine whisperer" since he was a toddler. He possesses an unbelievable focus on machinery and an ability to understand how it works and hear whether it's working right or not. We were watching an episode of Monty Python a couple years ago, he was mid teenage, and on the show a truck pulls up and stops. Then he says, "That truck's runnin' rich." and we believed him. We know better than not to.

He's expressed an interest in learning C++, and often suggests ways for me to do things, so I expect he might pick it up rather quickly.

[James D Jarvis]

I'm with ya. My son spends a lot of time on YouTube, but he's generally been using it in pursuit of "auto", as in auto-didactic automotive engineering. He's been a sort of "engine whisperer" since he was a toddler. He possesses an unbelievable focus on machinery and an ability to understand how it works and hear whether it's working right or not. We were watching an episode of Monty Python a couple years ago, he was mid teenage, and on the show a truck pulls up and stops. Then he says, "That truck's runnin' rich." and we believed him. We know better than not to.

He's expressed an interest in learning C++, and often suggests ways for me to do things, so I expect he might pick it up rather quickly.

Kids are amazing, just have to keep the world from messing them up before they are adults.