'On a clear night, you could never lose the stars,
and with them you could never be truly lost'
(David Baldacci)

The Polynesian Way.
The Polynesian Navigators knew their hemisphere so well that they naivigated by it without any instruments. This App will take the place of that knowledge. All you need is an accurate time piece, e.g. your phone.
This app offers two calculations.
The first one, is a 'Starfinder', that finds and identifies the 58 stars which are used by the Nautical Almanac.

The second calculation is that of a star's 'Sub-point'. The stars 'Sub-point' is the projected position directly underneath the star when the star is overhead, so that it's Declination and Right Ascension translate into latitude and longitude respectively.

If one has nothing else to navigate by, then the stars and a watch may give you some comfort that 'as Baldacci says' you should never be truly lost.
I hope you will enjoy this App!
PS
I assume that you are keeping track of a Dead Reckoning position.