There's nothing that can be more frustrating than dealing with an OS that just doesn't do what you want it to do.
That being said, Axiom has often provided pretty easy methods and information to follow.
In the case so far with the AxiomAir, i'm not impressed. Perhaps there is something easy that i just can't figure out because i find Apple OS to be entirely unintuitive, so perhaps someone can help (i got connected using my Android tablet the other day super easy; downloaded the app, saw the Air, started playing music with a Upnp app; simple).

Here are the instructions for connecting an Apple device to the Air when the Air is in hotspot mode.
To connect to the AxiomAir WiFi hotspot, simply join the AxiomAir-xxxxxx network. On iOS devices, a Safari window will automatically open to our WebUI.
Let's just stop right there.
Safari did not open up and presented nothing.
When i tried to manually enter in the WEBUi address (axiomair.local), i got the interface but absolutely nothing to help with the rest of the instructions on getting connected.

Anyone got a clue?
This should have been simple as pie, though anyone who has tried their hand at baking knows that making dough is actually an art and really not simple as described.

Ok, making some progress.
No Safari window popped up, but going to the Apple Music app, you can select the AppleAir playback and manually moving that to AxiomAir from iPhone did the trick.

Then i found another quirk.
It seems that if one selects tracks that are in the cloud while connected to the Axiom Air, the Apple music app 'disconnects' the AppleAir selection and goes back to its default (the phone or tablet for playback). Hence, clicking on a song in the cloud, which cannot playback because one is not connected to the internet, means that clicking on the next song which is physically on the iPhone also means having to select once again the AxiomAir under the AppleAirplay source.

Yeesh.

I'm still scared to think how multiple people can select music to the same queue when running two different OSes.

Running the system on the Android system was a bit easier, yet also more cumbersome. One needs two apps; the Axiom app and a uPNP app like Bubble Upnp.
The free version of Bubble is limited to a 16 song queue which is really small BUT, it plays both mp3 and flac files which is awesome.
Bubble also controls the Axiom Air volume directly so once it is up and running, you only use one app for all the processes.
Digging that at least.

Why does Apple suck so?

Continuing the story.
So understanding more about the Axiom Air and its queue. Only one person at a time can access the Air when using the Air as a hotspot. Correct me if i'm wrong.
Unless the Air is hooked up to a home wifi with a central music repository, and all the people wanting to add to the queue are using the Axiom app and queue system, then it is only one person at a time otherwise.
Good thing the Airplay password can be set on the Axiom, but does that also affect if Android units can access the Air?
Will an Android app or unit ask for the wifi password when this is set?

If so, excellent.
Anyone could be locked out with the simple change of a password by someone who knows the password, a plus and a minus.
Thankfully there is a factory reset button...