A year before I launched an app in google play store and it was running successfully in around 1000 devices.
Within the last year I have lost my laptop which has my keystore file and entire code of the app. Now I want to update the app in google play store. To update the app I have once again prepared the app as a new one and it’s ready for submission.
I know that I can’t update the old app without my old keystore, so I planned to submit my new code as a completely new app, but I need to intimate the existing users users about this.
There is a database in my app, so the existing users might have stored some data in them.
Now what I am planning is to submit the present code as a new app for future users and for the existing users I am yet to send a update via email or any other way that is possible. For this I want to know the list of persons who have installed my app and in whose device my app is been running. How to collect these data from my account in google play store and is there any way to send them a private notification to their devices without google play store ?
If it was a paid app, then you can get the email addresses from your merchant account order details.
If it was a free app, then the best you can do is put up notes in your old app description, and on your website if you have one.
Also, you should consider adding functionality to allow older users to import their database if it is possible (it will not be possible if it is on the internal private storage of the app).