How do apps get into the Connect IQ store’s home page collections?

What you specify on the dashboard isn't a 1 to 1 with categories in the store Different ones can be in the same category for example.  Where an app is shown within a category depends on different things, like rating, downloads, views.  There is no way to "nominate" an app, because everyone would be nominating their own.  Apps aren't in a consistent order can change often, where one day it's near the top of a category and the next day further down for example. When searching, you'll on see maybe the first 100-150 apps that fit the search, when there could be many times that that fit.

This reads like there's no method to the madness :) Is that how I should perceive it? 

I've been using the app store with my own apps for 11 years.  Even my apps with 100k downloads move around.  As more apps and more devs have started over that time, things might not be as clear as they once were

That's exactly how I see it.

Established developers with large download counts have held the top spots for years, while apps from new developers get buried almost immediately. Even some newly released apps with far fewer downloads and much worse ratings seem to rank higher than yours.

It's hard to understand why an app with just 10+ downloads and a single review would rank higher than another new app with 100+ or even 1,000+ downloads and ten reviews. Yet that's what we're seeing in the Connect IQ Store, and it's unclear what actually determines these rankings.

What makes this even more frustrating is that Garmin also regularly features new apps from certain established developers, even though those developers have already dominated the rankings across many categories for years. This gives them even more visibility and creates a deeply uneven playing field for new developers.

So should an app with 1000 downloads be more visible than one with 100k?  Users look for apps other people like and use, and have used for a while.  It's like when you go to any store.  You'll tend to look at brands you know and not ones you've never heard of, and if the cost is the same (or even "free" in the app store), you'll likely pick the well known brand.

Also remember that there are a whole bunch of devs in the same boat as you.  Which should show?

The "order" isn't just rankings  and downloads, but also includes "views" from things like social media where the apps never even get installed.  I never liked that "views" were included.

That’s not what I said. I never argued that an app with 1k downloads should outrank one with 100k. My example was the opposite: an app with 10+ downloads and a single review ranking above apps with 100+ or 1k+ downloads and ten reviews. That isn’t a hard trade-off between proven and new. It’s a result that doesn’t follow any logic a developer can see.

On views: where does that come from? I haven’t found anything from Garmin documenting that views count toward the order. If there’s an official source, I’d really like to see it, because that would explain a lot. If there isn’t, then that’s exactly my point: even experienced people here are guessing how the ranking works, because Garmin has never published its main ranking parameters.

I recall that there were Garmin posts in the forums here when "views" were included, but don't recall exactly when. But is was very clear when it happened, as you now see.  Apps with few downloads getting visibility, because other devs complained that all they saw were apps with very high download counts and high reviews. I have an app that used to be highly visible with 700k downloads for example.