Create a file in cordova is pretty easy, use the following code to create file in a specific folder. This code works in all cordova platforms ()
var path = "file:///storage/emulated/0";
var filename = "myfile.txt";
window.resolveLocalFileSystemURL(path, function(dir) {
dir.getFile(filename, {create:true}, function(fileEntry) {
// The file has been succesfully created. Use fileEntry to read the content or delete the file
});
});
Remember that you need the file plugin from cordova, read and learn how to use it here. You can download the file plugin into your project with :
cordova plugin add cordova-plugin-file