I like my instinct, but Garmin is so locked down, less hackable than even an Apple Watch.
It's a lucky day when someone from Garmin graces Forums with their presence and bestows few sentences they think could pass for an answer.
In other words, yeah, the SDK is free, you can side-load and it’s not hard to write for, but you just can't write much.
> Monkey C compiles into byte code that is interpreted by a virtual machine, similar to Java.
https://developer.garmin.com/connect-iq/reference-guides/mon..., 2nd paragraph.
> Don’t know about Apple Watch development
Garmin has refused to fix this for many many years, and there's no games you can play with SDK that will help you fix it yourself
I've written my own little app for my Garmin watch, and I didn't need to get permission from them or pay them anything.