I simply will not use my personal phone for work purposes. I hesitate to even make a call in a pinch. There's no way employer mandated apps are going on there.

I simply will not use my personal phone for work purposes. I hesitate to even make a call in a pinch. There's no way employer mandated apps are going on there. If an employer doesn't provide a phone but expects these things, I will simply make them figure it out / work out an alternative solution with them. In the worst case I would be prepared to be fired over this issue.