There are 3 repositories under bcsamples topic.
[PREVIEW] The Take Order sample demonstrates how you can build a customized user experience for servers at restaurants, using Power Apps powered by Business Central.
[PREVIEW] The Warehouse Helper sample consists of an AL extension, a Power App, and a Power Automate flow. The app can scan a barcode and attempt to map the value to a Business Central item's GTIN property.
Sample Per Tenant Extension, implementing an integration with Bing Maps inside Business Central.