Update #2: Mobius USB tools has been back for a while and works again. therau2000 likely changed his name to iMobiusMike given all the bad press he got, but once burnt twice shy. I do not encourage you to buy his app, no matter what he promises, given how he royally screwed his users in the past. Tomas Chladek's Mobius ActionCam app works fine now, use that one.
Update 2015/12/23: Kudos for Tomas Chladek for having stepped up and added USB support to his Mobius ActionCam and app. Thanks to him, and for a very reasonable price, one can update/reconfigure mobius cameras in the field without a computer.
Sigh, I was on the field with my RC plane and need to change the contrast on my mobius cameras before taking off, and when I started Mobius USB Tools, I was greeted by a screen that said it wasn't supported anymore and that I had the option of uninstalling it.
I just spend a few hours today looking into WTF happened, and sadly the author, firstname.lastname@example.org deliberately sabotaged his very nice app and screwed all his users in the process.
What seems to have happened is that he was hoping to get money from mobius for each camera sold in return of his work. To be fair, he did put in a lot of work, and the result was a great app that helped a lot of people. I write open source myself and give it away to help others too, so I know how this works, well except that I've likely spent less time on it and also I don't expect compensation in return
Mobius apparently declined to provide whatever compensation he asked for (or maybe it was an ultimatum or shakedown, hard to say), and in turn he decided to kill his app and screw all his users who would have been happy to give him money for his work, but never were given the chance to.
This is where the app used to be: https://web.archive.org/web/20150708002619/https://play.google.com/store/apps/details?id=therau2000.amcamobiusac
I checked http://www.appdownloader.net/Android/App/81629/therau2000.amcamobiusac to see if I could just go back to an earlier APK that wasn't sabotaged, but I found out that he clearly had planned to do this a long time ago and sabotaged all his apks so that they would not work when a new version was out. I've gone all the way back to 'Mobius USB Config (aMCA) 22.214.171.124' from 2014, and it tells you to upgrade to a newer version instead of working. I tried a few versions in the middle of none of them worked in a useful fashion, even in airplane mode.
Obviously the author has the right of screwing over all his users like he did, but it's really a dick move, and instead of being mad a mobius like he was hoping I/we'd be, I'm mad at him for throwing away his good work, and screwing all his users. While http://webcache.googleusercontent.com/search?q=cache:U9hpWobhL5kJ:pages.videotron.com/therau20/nr16/android.html+&cd=1&hl=en&ct=clnk&gl=us claims "There has never been any intention on my part to hurt any of the 16,160 Mobius USB Tools Users", that is exactly what he did. Saying otherwise on a web page is BS.
Sadly, the replacement options aren't as good. You can get https://play.google.com/store/apps/details?id=cz.chladek.mobiusactioncam but it doesn't have the code to mount the sdcard via USB, it's meant for you to put the microusb card from your mobius inside your phone (this has now been fixed, please use this app).
If your phone is rooted, in theory you can use https://play.google.com/store/apps/details?id=eu.chainfire.stickmount to mount your mobius locally and hope the other app lets you edit the settings directly.
https://play.google.com/store/apps/details?id=com.vaultmicro.camerafi&hl=en is supposed to let you see video from camera (press the recording button after plugging the mobius in to switch to webcam mode).
I personally would prefer that someone hacks the last good known version of therau2000.amcamobiusac and removes the disable code. Anyway, sad state of affairs for mobius and android users.
That said, for now, my workaround is to use my rooted phone where I can run stickmount if everything works well, then it mounts the mobius under /sdcard/usbmount/sda1 where in turn the "mobius actioncam" app can mount a syscfg.txt file that I first need to create with long press menu, long press power on (with camera unplugged). I've also verified that long press on the camera button does turn the camera into webcam mode, and then it works with 'camera fi' to see where the lens in pointing.
(on a good day it also seems that my marshmallow phones can mount the mobius as a usb storage device, only using basic OS support, but I have no idea where it's mounted, and that feature doesn't seem to be reliable at all)