Microsoft-provided, open-source code for document-signing in Microsoft Teams meetings
This actually isn’t a completely new sample, but I missed it when it was first talked about earlier this year. A blog post in the Microsoft Tech Community brought it to my attention.
Microsoft have made available an open-source proof-of-concept project, showcasing the ability to undertake document signing in a Microsoft Teams meeting. This would be useful for, say, NDAs, Purchase Orders, or even code reviews, manager assessments, holiday requests etc.

Because the app is being hosted within a Teams meeting, authentication is frictionless and uses Teams SSO.
For a POC, it’s quite advanced, with a document-creation process and different views depending on role. There’s enough in here for a developer or development team to take as a good starting point, before customising for a particular organisation or workflow.
The code is open-source at: https://github.com/OfficeDev/Microsoft-Teams-Samples/tree/main/samples/meetings-share-to-stage-signing/csharp
There is also a walkthrough video, which covers the “why” of the project, high-level process flows, and explanation of how the code works (watch from 15 mins):