@mathew butterfield Thanks for posting in our Q&A.
From your description, did you mean that you want to add your in-house app to intune and deploy it? If yes, line-of-business app will make it.
https://video2.skills-academy.com/en-us/microsoft-365/solutions/apps-type-lob?view=o365-worldwide
Here is an article showing that how to add the LOB app.
https://video2.skills-academy.com/en-us/mem/intune/apps/lob-apps-windows
If there is any misunderstanding, please correct me.
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