Which running/biking apps (Strava, Runtastic, Endomondo, ...) use barometer for proper elevation gain? After having read this blog (More GPS Cycling Tests: Things are Pretty Bad and There’s Little Hope) about the inaccuracies in apps like Strava and Runtastic, I'm curious which similar apps produces reasonably accurate elevation gain/profile.

Here, Runmeter seems a good option. But which others have you found?
I would consider an app reasonably accurate if it produced results close to a Sigma bike computer with altimeter.
iSmoothRun records elevation data using the iPhone's barometric altimeter. This app can sync with various storage and tracking services, such as Dropbox, RunKeeper, Strava, etc.

The barometric data is preserved when syncing or exporting GPX/TCX files from iSmoothRun (although I currently have to tweak the header of the GPX file and manually upload to Strava in order for Strava to respect the barometric data recorded by iSmoothRun instead of discarding it in favor of its own measurements based on topographic data).