sign key keystore
for example:
jarsigner -verbose -keystore my-release-key.keystore looptek3ddemo.apk alias_name
jarsigner -verbose -keystore my-release-key.keystore PowenKoKeyboard.apk alias_name
jarsigner -verbose -keystore my-release-key.keystore PowenKoZhuYinIME.apk alias_name