This was used for signing an apk built with buildozer and made with kivy.

keytool -genkey -v -keystore my-release-key.keystore -alias alias_name -keyalg RSA -keysize 2048 -validity 10000

Above command will recommend this so do it:

keytool -importkeystore -srckeystore my-release-key.keystore -destkeystore my-release-key.keystore -deststoretype pkcs12

jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore my-release-key.keystore my_application.apk alias_name

This is required for uploading to the Play Store. It aligns the data in apk to start on 4 byte boundaries for faster memory access and reduced memory consumption.

Install tool

sudo apt install zipalign

Align

zipalign -v 4 my_application.apk-signed.apk my_application.apk-signed-aligned.apk

• Xubuntu 20.04.1
• Buildozer 1.2.0
• kivy 2.0.0

• https://stackoverflow.com/a/17777071/6881647
• https://developer.android.com/studio/publish/app-signing