I care very deeply about privacy, and so can confirm that your personal data is never transmitted to me from any apps in the Windows Store – any logins are safe.
Some apps may store your settings in your Microsoft Account, meaning you don’t need to setup the apps on a new device. There’s no method within the apps to turn this off, however you can turn this off system wide.
I also have anonymous analytics on my apps – these transmit basic usage stats and errors to Microsoft so I can improve the apps. No personal details or logins are transmitted as part of these analytics, and I don’t sell anything I receive.
If you don’t agree to these terms, feel free to bug me to add settings to disable the MS account settings and analytics.