I do have that problem, which is why I appreciate the warning chimes of my Pomodoro app. But I prefer my warnings to be in the audio mode, especially because I don't have to remember to pick up the phone to see what I'm forgetting.
It’s funny how different brains work. For her, any sound feels like an interruption or a 'demand' from the phone. She prefers the visual cue because it lets her check the time on her terms, rather than the phone interrupting her flow.
But you're right—for 'eyes-free' awareness, you really can't beat audio.
