Steps in Creating an application from the developer portal: 

1. Click on Build Custom Apps from your developer portal. This will display the Creator Home page.
2. Click on Create App link displayed on the top-right corner of this page. 
3. Specify the Application Name and click on Create.
4. The application with the specified name will be created and listed in the App Details page.
5. Click on Develop App to add Forms, Reports and Pages to your application.  Refer Creator Help  for more information on creating your application.
6. You can publish the app to your clients or in the Zoho Creator Market place.