I have successfully created a signed release version of an app for beta-testing.
To download it onto a phone I have placed it on a website where I can give the specific URL out to potential beta-testers. Testing out the download works, and ultimately I get it onto the phone, however I had to go into settings and enable the option to allow unsafe apps, then click numerous times to ignore any issues, and go ahead with this unsafe app etc. It's enough to scare anyone off!
I think it was Play Protect kicking in. But my point is that my beta-testers may, understandably be very wary of so many warnings coming up, and so decline to take part.
What is play protect checking for, before deciding it is unsafe? Is it just that the app didn't come from Google Play? Is it something to do with the signing authority? Or is it checking for certain permissions, or behaviours?
Thanks for any advice, I'm just not sure what I need to do to make the app safe enough for beta-testers to feel comfortable.