After All the setup, To make Hello World App
ionic start HelloWorld blank // create new project
cd HelloWorld // get into HelloWorld directory
<body ng-app="starter">
<ion-pane>
<ion-header-bar class="bar-stable">
<h1 class="title">Ionic Hello World App</h1>
</ion-header-bar>
<ion-content>
<div class="center">Hello World..!</div>
</ion-content>
</ion-pane>
</body>
ionic serve // run the app in browser
ionic platform add android // add android platform
ionic platform add ios // add ios platform
adb devices // to check devices is connected
ionic run android // to run on android devices
ionic run ios // to run on ios devices
ionic run android -c -s -l // to check app in live reload with console.