[lug] OT: android elevation app accuracy

[Davide Del Vento]

Folks,
I need to measure the height of two corners of the house (outside) and
I was wondering if the "elevation" (barometer?) apps are accurate down
to the inch (or better). Of course I don't care about absolute
accuracy (i.e. I don't need to know how many inches I'm above sea
level) but relative accuracy (i.e. how much slope there is, if any,
between these two corners).
I know the GPS won't do it, but how about the barometer? Note that my
phone is a GSM from the 90s so I'll have to borrow one...
Cheers,
Davide