I've developed my app 3 years ago on Titanium Appcelerator platform. I didn't use custom JKS for signing. Titaniume gave me ready APK and I uploaded it to Google Play, during 3 years I did 10 updates without problems.
Now I developed native Android App with the same package name. But I cannot find ".jks" file for signing. Without it Google Play will not accept as an update. How can I find that file for sign?