Hi Sergiy, thank you for your help. If anyone else is struggling hope this helps
after using this tutorial
https://devcenter.appery.io/tutorials/jqm/building-a-mobile-app-with-google-map-and-geolocation/
Added javascript file with
var aofMarkers=[];
function RemoveMarkersfromMapp() {
var i;
for (i=0; i< aofMarkers.length; i++){
aofMarkers.setMap (null);
}
aofMarkers = [1];
}
then on success of convert_address javascript add aofMarkers.push(marker); line
var markerLatLng = new google.maps.LatLng(localStorage.getItem('markerLat'), localStorage.getItem('markerLng'));
var marker = new google.maps.Marker({
position: markerLatLng,
map: map,
title: data.results[0].address_components[0].long_name,
animation: google.maps.Animation.DROP
});
aofMarkers.push(marker); ///////////// added this line
bounds.extend(markerLatLng);
map.fitBounds(bounds);
then call the RemoveMarkersfromMapp function
RemoveMarkersfromMapp();
to clear markers, i fund the easiest way to do it on a button command