Question: which one of the following tools creates certificates for signing android applications?
Answer: Generate a private key using keytool. For example: $ keytool -genkey -v -keystore my-release-key.keystore. -alias alias_name -keyalg RSA -keysize 2048 -validity 10000.
Compile your app in release mode to obtain an unsigned APK.
Sign your app with your private key using jarsigner: