Provide users of a purchased android app access to another app

Question

I own a paid app, which I refactored almost completely within the last weeks. Now I want to update and am now facing the issue that:

1. Just updating the app would make users lose all their data as also internal structues have changed. -> no-go

   Furthermore as I got rid of a lot of compatibility stuff and are now targeting only Android > 4 I would be unable to provide separate fixes for pre Androdi 4 targets.

2. Releasing as new App (2.0 or something) would exclude existing users who already paid.

Per se I prefer option 2 as existing users would not be affected and I would still be able to provide limited support to older devices. I also like the idea of being able to restart again.

But, how can I enable users of my old version to use the new one without having to pay again?

• ignoring this issue will make them angry (of course)
• android promotional codes are limited to 500 per quarter. Like this it would only take three years if about half of my active users would upgrade
• releasing a free version with in app purchases and provide existing users with a code / check if paid verion is installed -> too much compatibility stuff to consider. Also I like it to directly see the costs of an app and not having "hidden" costs.
• Refunding as (as proposed in https://stackoverflow.com/a/14694981/570168) also does not seem to pe a practical solution for me (considering the mass of affected transactions).

Am I'm missing any other option?

Answer 1

I now just released an update which creates a backup in the background. So I will wait a few days or maybe weeks for most of my users to update an then publish that new app which will then import the previously created backup.