Backwards compatibility for Windows Phone 8.0 apps

Question

I've got a small app that was built and shipped for Windows Phone 8.0. I need to publish a small update and I'm encountering all sorts of IDE bugs & missing classes/types when upgrading to VS2015/WP8.1 platform.

So, I'd like simply to keep the app at WP 8.0 but:

Question 1: Will this app run on WP 8.1 and Windows 10 phones?

Question 2: Will Microsoft's app store let me publish this update despite target platform being 8.0?

Answer 1

Firstly, Microsoft provides awesome backward compatibility when it comes to running your old OS apps on new devices. As per your question,

1. Yes, all your apps that were built to target windowsphone 8.0 OS will run successfully with no issues on all latest windows supported MOBILE devices.

I have tested my old Windowsphone 8.0 OS apps on latest windows 10 preview without any issues.

2. You can easily support your app with new updates based on windowsphone 8.0 OS. You will have no problem submitting your ( .xap ) packages on the new Windows 10 dashboard.

A large portion of windowsphone mobile devices ,the old lumias still don't have windows 10 yet so there is still a market for your apps. You don't have to consider your apps dead just because you belong to an older OS version.