Contract Android developer left, need to update the application without the original keystore - is it possible?

Question

Our contracted Android developer provided us with the source code of the work performed for us, as per our contract. After the contract finished, the developer became busy and is now not reachable. We are moving to another developer to maintain the application. However, we do not have the first developer's keystore so the application is not allowing us to update it.

Is there anyway for us to maintain this application if we cannot get ahold of the original developer? We have lots of customers who have the app with data they have generated, and they need our updates.

Answer 1

No you can't update your app on the store without the published keystore.

You can publish the app with another name and keystore (a new app so with a different package name) but you can't update it.

Answer 2

If you have push notification feature in your old App then you can send a push to all your user that there is another updated version is available.

And Just upload updated version with different package name. And even you can send play store link in that push message as well. Most of people use this technique and they got success to move all user from old app to new.