As a fully remote/flexible/async SW developer contractor paid by the hour, I have a different situation than most.
Personally I do not install any work apps on my phone because I could easily end up "doing work" that I don't really get paid for.
When I work, I sit down at my actual PC intentionally, I start a timer, and I bill for my time that I take doing work only.
I avoid any work that I need to respond to outside of that and I make this fact known to anyone I work with.