> For the complete documentation index, see [llms.txt](https://developers.felt.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.felt.com/js-sdk/sample-application.md). # Sample application This is a sample application showing how to use the Felt SDK to build an app with the following features: * listing the map's layers * toggling layer visibility * moving the viewport to center it on predefined city locations

The sample Felt SDK Application

The commented code in its entirety is shown below. ```html Felt JS SDK
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