Congratulations. Your spreadsheet has become an app.

Copilot Cowork and Copilot Studio are getting conversational app building. Great. Now decide who owns the app after the demo.

Every organization has a spreadsheet that is one vacation away from becoming an incident.

One person understands it. Everyone else knows which cells they’re allowed to touch. Naturally, it runs something important.

That is the kind of problem worth bringing to Copilot’s new app-building experience.

In its September 10 announcement, Microsoft introduced conversational app building through the /app skill in Copilot Cowork, available through Frontier. It also announced a public-preview rollout in Copilot Studio over the following week. That does not establish availability in your organization today.

Describe the users, data and actions you need, then refine the result through conversation. Microsoft says the apps can connect to business systems and write results back. Published apps appear in the Microsoft 365 admin center, with organizational identity and data policies respected by default. Building and running them uses usage-based billing.

Translation: “I made an app” is the beginning of a conversation. The finance department may also wish to join.

The demo is easy to applaud. Who owns Tuesday?

Before sharing a new app with the department, answer four questions:

• Who owns it when the person who built it is away?
• What can it read or change, and who should be allowed to use it?
• Has someone tested mistakes, missing information and incorrect results?
• Who is watching the running cost?

Start with a small, annoying task and dummy data. Let the people doing the work shape the solution. Bring IT in while the app is still easy to change, and agree on what must be checked before it touches real records.

Employees often know exactly where the friction is. Giving them a way to fix it is a good thing.

Congratulations. Your spreadsheet has become an app. Please don’t let “ask whoever built it” become the support plan.

Source: Microsoft’s app-building announcement, September 10, 2026; checked September 16. Commentary and suggested evaluation steps, not a hands-on test or a promise of access under any particular license. A work account alone does not establish eligibility or included usage.