This superpower to appear and disappear at will would work perfectly for me throughout the day.
When I’m running late, I know that I’m not really late – I just have to make sure I use my superpower to appear a min. before the event or be somewhere. This can save me so much time on transportation and give me time to do so many other things. I sometimes have to travel a good hour for my job, and that hour would (hopefully) used productively in reading, studying, etc.
As for disappearing, I would use it for situations I don’t want to be in. Like if my friend somehow persuaded me to go to a place that I didn’t want to go to – just disappear.
The only downside to the superpower would be that I would be walking less. The answer to that? Use my superpower to show up at the gym early in the morning – no motivation required to “go to the gym” because I’ll be there already.