How to create an overlay page in ionic 2?

How to creating an transparent guide overlay page when i enter into new page

How can i implement in ionic 2 ?

add a modal without header bar and style it?
transparent background and so on

this is correct?

and this page show only one time after install

ionViewLoaded(characterNum) {
  let modal = Modal.create(ModalsContentPage, characterNum);
  this.nav.present(modal);

}

for only showing 1 time when first open the app you can store a value in localstorage after displaying the modal and ignore when there are already a value in localstorage…
for example

if(!localstorage.getItem(“FirstTime”)){
let modal = Modal.create(ModalsContentPage, characterNum);
this.nav.present(modal);
}