If you have the Owner or Creator permission of a workspace, then you can see the "+ New Application" button from the top-right of this worksapce.

Click the "+ New Application" button to create a new application. There are 3 options: start with a template, start from scratch or import from a local template file.

Click "Start with a template" to enter the template library with all the available application templates.

You can choose by categories or type keywords to search the template you want from the left bar of the library.

Click on the template you prefer to try to see its introduction page.

Click the "Use template" button to create the application with this template.

After the template is installed, you can try to use and customize it per your needs.

Click the "Start from scratch" to create a new application. In the pop-up window, fill in the required information properly:

(1) Set the icon for the application. You can select an icon provided by system or upload a custom one.

(2) Fill in the application name and description. Please note that applications' names cannot be duplicated.

If you have any exported application template, you can import application from those template file. To learn more about how to export and import applications please refer:

Export and import applications

You can check this article to get more information of application permissions:

Permission groups for workspaces and applications