Write an Android application

Need to create an android and iOS application shell based off OsmAnd open source software. If you would like to bid only for android or ios that is ok as well, just indicate so. Basic requirements -> online and offline navigation and routing on vector maps using open street maps. There are two open source applications that have this functionality already (osmand and osmsharp). Programming needs to be in native device code (not on Xamarin). App needs to have ability to download the offline map section (select area from continent->country->province->city selections) from independent menu. App needs ability to view my own dataset of points on map (connect to web api via REST) to pull POI via lat/lng. Needs ability to view my own route on map as well (sync with way points of some path (point a,b,c,d,e,f,g) from web) then be able to use in app routing to navigate between those points in succession. User should have ability to mark points as "seen", so that navigation does not route user to that point again. if user deviates from path, to be able to reroute to the nearest waypoint OR reroute to the next specified waypoint (if path was supposed to be point a,b,c,d,e,f user is between points b and c, he should have a choice to go next to point d or to nearest point (which may be one of d,e, or f). Ability to add or remove waypoints on the path (so each "path" should be saved as some item.