Pumps with apps and I have a flip phone

Hello, I've been looking at the eufy s1 pros. My insurance will cover it (and I was given a pumpable genie advanced from a friend and another said I can have her spectra.) So really I'm in need of a more portable/discrete pump currently. I really am liking everything I see about the s1 pros, but everything I see reddit about them talks about the app. Do you have to use the app? And so many other pumps use apps. I'm feeling a little lost in the world of pumps. help....