Thanks, yep comes in at 3 MB. It's all Swift and Metal. I'm a web developer by trade, done that at a high level for 20 years including Amazon, Google, other big tech, but this was my first native app and first time using Swift. At the moment I'm learning all about weak refs and reference cycles causing memory to be retained when you don't want it to be.
And I just discovered there's a group in Seattle called XCoders (https://xcoders.org/), I'll drop in on their social next week and maybe learn more about the Swift/Apple ecosystem.