Can't update Camera app [not relevant]

What camera app?, if you are referring to the normal camera app that is installed as part of SFOS, then I doubt there is any kind of update available from Jolla Store, even the camera app is not available for download.

I don't know. I have used SFOS for just a couple of weeks and I have never installed any camera app on my own, so therefore I assumed that this camera app from Americanmegatrends, referred to the default camera app in SFOS. If that is not the case, then the problem is not very interesting, I suppose.

If you don't know how can we have any idea what you are talking about?. What is the name of this camera app? and/or which store are you finding this application/update in?, is this a Sailfish App or an Android app? AmericanMegatrends generally are related to BIOS software not camera apps, all sounds a bit weird to me.

By default with SailfishOS, you should have a camera app already installed on your device, this should also only be a Sailfish application, the only way to update the camera is to update the OS, there are no updates offered by Jolla in the Jolla Store for the camera, so I have literally no idea what you are talking about - the more info/images you can give, the better the help you will receive.

From what I can see or at least what I can understand is, that you are trying to install an Android app that is not compatible with the Alien Dalvik (Android layer) of your device. This happens because the app in question requires a higher Android version than that used by the Alien Dalvik, so the install fails - I would say stick with the sailfish camera app that comes with the OS, but from what I read, that gives pretty awful images; I'm still using Jolla1 (the very first SailfishOS device) and the built in camera app.

It is "Camera (AOSP) 2.0.002 (AMERICANMEGATRENDS) The description reads: "Android Open Source app from Remix OS 2.0. Working on all devices expected TVs". As I said, I am a new user and I don't recall having installed this app, ever. So I assumed that it was the default camera app that I use to take pictures with my phone, and therefore I would like the updates to work. If it is not important, then where does it come from and how do I get rid of it?

Okay, fair enough, I understand you are a new user, as I was 5 years ago coming from Nokia N9, I also did not have a clue at that time...anyway, to get rid of an application from Sailfish can work 1 of 2 ways, FIRSTLY, always (if possible) return the 'store', find the app and choose to uninstall it, OR long press on the launcher to activate the X on each app, this now means if you tap on the X the app gets uninstalled - alternatively, you will need to fire up Developer Mode and type a line of code such as; "devel-su pkcon remove the-crappy-camera-app" As a new user, you probably do not have Developer Mode activated. Developer Mode is found in Settings, when you activate developer mode, you will be asked to create a password, remember it and when using terminal, you will sometimes get asked fro your 'password'.