I think people who are into rocketry use that device to record maximum altitude. Does it have a mode that allows you to continuously observe pressure changes within the housing. How long does it remain on? Something like that would certainly be an improvement over the usual red/green light indicators.
I see that there is also an "altimetertwo" and an "altimeter3." Do you know how they differ from yours. I think the altimeter3 can de controlled by an iPhone.
Right now, I'm using a rather large aneroid barometer the same way. However, once installed, it shifted some housing controls out of alignment - to fix that problem, I had to I shave quite a bite of material off the bezel and off the back of the thing.