Unattended access is availible for PC with TeamViewer.
Could Android devices be also accessable in an unattended mode or the Android user should allow an access each time (attended mode)?
I am also new to this and wondered the same thing. After some trial and error, I believe that what you are asking is definitely possible. Once you have your account set-up and TeamViewer installed on your computer as well as TeamViewer app installed on your Android you should be able to. I did go through the process of allowing unattended access on the desktop app. I also made sure that both devices were added as trusted devices in my TeamViewer account. After all of this I went to the login page in Chrome and logged in to my account, When the team viewer management console came up I clicked on "My Computers" in the menu on the far left. This brought up both my Note 8 and my laptop. I clicked the "connect" button beside my note 8's device name and it brought up the TeamViewer desktop app and began a connection with my android device without any prompts or need for authorization on my phone. I was able to perform all functions without issue. Unsure if this matters but I DID have the TeamViewer app running in the background on my Android phone. I will try the same process with the app closed and see what happens but in the interim this process worked for me. No clue if I did this correctly or if I went through 50 steps when I could have gotten same result doing 5 steps. I took the trial and error approach to figure it out so if I am wrong please don't hold it against me. If I do end up having to leave the app running in the background to get unattended access to my phone that is fine. It's a small sacrifice to make to make sure this awesome program works. If anyone else out there reads this and wants to correct me or through some guidance my way I am all ears and very grateful.
Hope this helps...