I have a Jolla phone, that one phone that runs the only operating true Linux distro, after Ubuntu gave up, called Sailfish OS.
I tried downloading the mobile apks, but I could not run them. I don’t know why.
has a google play clone store, not everything shows up there. I don’t know why.
F-droid is a FOSS android store where everything does show up and have had success installing apps on my phone, which is why I request this.
We’ll surely be looking at publishing apps to various stores eventually(starting with few and scaling to more), for now though they arent published to any stores for any platform as they are merely just PoCs showcasing system compatibility in mobile more than anything else. Even for android devices these require enabling apps from unknown publishers.
Not having used this phone/OS cant comment on how you could go about installing it via the apk directly but there seem to be a few articles talking about the same that may help
Installing applications from .apk files
How to install APKs on Jolla?
Some threads talk about using “Jolla File Browser” and needing to restart a particular service/installing some default app to enable particular features as troubleshooting tips, but the jollausers forums likely can help more in terms of installing an app direct via apk.
Again just to be clear, these are just useful if someone wants to try test compatibility and arent intended as production deployment routes.