Tips for updating existing Windows Phone 7 apps in the Windows Phone MarketPlace for Windows Phone 8 users.
As a developer you can update both your Windows Phone 7 and Windows Phone 8 apps in the Microsoft Dev Center and republish any amendments or changes. I have had a few questions about with path in Dev Center should I follow to ensure both my apps are updated accurately.
The Microsoft Dev Center supports multiple XAPs for any app.
Therefore as a developer you can choose to have a single XAP (typically targeting Windows Phone 7) or have two XAPs (one for Windows Phone 7 and one for Windows Phone 8) by doing this the app has a single GUID, and has a optimised experience for each platform.
What happens if I build a new version of my existing Windows Phone 7 app in the new Windows Phone 8 SDK?
If you have updated an existing XAP with a new Windows Phone 8 XAP, you potentially risk eliminating the Windows Phone 7 version.
To mitigate any issues take one of the following steps.
1. To Keep a single XAP which works on Windows Phone 8 and Windows Phone 7
Recompile the Windows Phone 7 app with the new Windows Phone 8 SDK and update the XAP file. NB. This is ideal scenario if your app doesn't require use of any of the Windows Phone APIs. However if your app takes advanatage of the Windows Phone 8 APIs please use option 2 below.
2. To enable two versions of your app. One for Windows Phone 8 and one for Windows Phone 7
You will need to create the new Windows Phone 8 version and utilise the new APIs and then add this new Phones 8 XAP to the Dev Center.
To Add your app to the Dev Center
1. Login to the Dev Center https://dev.windowsphone.com/en-us
2. Select ‘add new’
3. Upload your new Windows Phone 7 and Windows Phone 8 XAP (ensure version number is higher on the Windows Phone 8 XAP than your existing or new Windows Phone 7 XAP)
4. Add meta data (NB. Please ensure the country list and language support selected is identical on both XAPs, if these do not match your app will NOT Appear in search Windows Phone now has 191 new markets so developers need to ensure they cross submit to take advantage of these new markets and consumers.
5. Click Submit
6. Your new apps will then be tested and published if they pass all necessary checks.
Here’s the official doc page on the upgrade process in the tools:
How to upgrade an app project to WP8: msdn.microsoft.com/.../jj207030(v=vs.105).aspx
How to target multiple versions with your app for Windows Phone: msdn.microsoft.com/.../jj206997(v=vs.105).aspx
‘light up’ for IAP and Tiles should be part of this conversation, (they’re ways to add wp8 functionality to apps compiled to wp7),
IAP light up: here: channel9.msdn.com/.../Inside-Windows-Phone-45--Adding-In-App-Purchase-as-a-light-up-feature-to-your-Windows-Phone-7-Games