I don’t know if you are still looking for an answer on this question. I have made a workaround thats maybe not a something that is very nice, but its up to you what you think about it.
Just place this in every page that is a tab.
You can even do anything you want in the ionViewDidEnter, so if you want to let the user do something with an alert to confirm quiting, you can.
// register backbutton to quit the app if its on this page
ionViewDidEnter() {
this.platform.registerBackButtonAction(() => {
this.platform.exitApp();
});
}
// register backbutton to pop a page when on backbutton pressed
// If you switch from tabs then it will first do this method, and then on the other tab it will overwrite this action
ionViewWillLeave() {
this.platform.registerBackButtonAction(() => {
this.navctrl.pop();
});
}