Yeah phone apps are horrible, don't know about iOS since I've always used Android, but they're mostly bad. The apps geared to a company service are usually fine, but the rest are just ad support systems.
I actually don't use third party phone apps that much, but the times I have it's like an assault. You get a tenth of the screen for the actual function of the app with the rest of the screen gyrating ads. It's especially a problem for me because I'm old and can't see the screen that well. I don't know how people put up with it. I can't.