I have one application in Google Play, Now I had developed one new Application to replace this current android application, Existing application and New Application has different Application Name, Package Name . So I just want to know that Can I use Existing application (Which is currently in market) keystore for creating new application signed apk file?
My requirement is Existing user will gate alert that new version is available after updating user will get New Application on there device.
I dont want to maintain two seperate apk files (existing application which is in market and New one)
My requirement is Existing user will gate alert that new version is available
To give users alert that a newer version is available you will have to keep the package name and signing key same and increase the app version number and version code.
Can I use Existing application (Which is currently in market) keystore for creating new application signed apk file
Yes. You can use same keystore to sign any number of applications you want.
But remember signing an app (with different package name) with same keystore does not make it an update to existing app. If package name is different, it will be treated as a brand new application.