Microsoft just launched its new Lumia 950 smartphone this week with Windows 10 Mobile, and it wants to entice you to make the switch. That's likely the reason for the company to also launch its latest Android exclusive app, AppComparison.
The purpose of the app is to match your already-installed Android apps with some Windows Phone variants. As the app description says:
Are you considering changing your Android device to Windows Phone? AppComparison identifies your favourite Android apps and matches them with apps available from the Microsoft Store. The application also introduces you to some of the most popular Windows Phone applications.
You can download Microsoft's AppComparison from Google Play.