Thanks for the reply @james_nz . yeah I want my app to work same like the google map works. I get my route from my server where i calculate my routes using graph-hopper and then receive a response from the server having poly-line coordinates and the routing instructions with distance and time. I would like to utilize these data’s and want my app to tell the users when to make the turn. I tried with comparing the current location and linestring coordinates but that not a good idea because the geolocation accuracy may be wrong sometimes. so I was searching for a new algorithm or a solution that fits with my app.