PolarAlign is used as a reference to help "polar align" an equitorial telescope mount that has a Polar Alignment scope. PolarAlign uses iPhones Location Service to obtain your current latitude and longitude, although they can be entered manually.
The screen shows the position of Polaris if you are in the northern hemisphere or Sigma Octanis if you are in the southern hemisphere. It also displays your latitude, longitude, altitude and universal time, along with the local sidereal time (LST) and hour angle (H.A.) of Polaris.
The view can be zoomed by double tapping the screen. The PolarAlign generic reticle can be set to inverted, corrected, or right angle, to match the polar finder. Alternatively, three different Takahashi reticles or the Astro-Physics RAPAS reticle can be selected.
PolarAlign has an "augmented reality" capability which allows an iPhone to be mated to a polar finder scope, if you build a simple adapter.