All objects in the Qlik Sense user interface are created with standard web technologies and use the standardized API to communicate with other parts of the product. This means that it is straightforward to create your own visualizations—given that you are familiar with programming and HTML5. Such visualizations are called extensions.
There are a number of extensions available that can be downloaded from the Internet. If you download extensions and want to use them with Qlik Sense Desktop, you should put them in C:Users<user>DocumentsQlikSenseExtensions. If you want to use them in the Qlik Sense server, you need to import them using the Qlik Sense Management Console.
Once you have done this, the extensions will appear in the assets panel to the left when you edit a sheet.
The Assets panel will display both the standard objects and extensions.
If you want to create your own visualization, Workbench is a good place to start. Just start your Qlik Sense Desktop, open an Internet browser, and go to http://localhost:4848/Workbench.
The Qlik Sense Workbench
This will open a web page that allows you to create extensions and edit the existing ones. If you click on Create new, you will be prompted for a name and on which template it should be based.
Once the visualization is created, you can edit all the files through this user interface: the JavaScript code, the CSS file, and the metadata.