The auto-signing tool is a GUI application based on signapk.jar for Windows, and can sign multiple apk and zip files very quickly in one click. It also features a drag and drop function and supports signing with privatekey.pk8 and publickey.x509.pem.

The tool can also sign a mixture of apk and zip files together – you just need to extract the archive the dev has provided, launch, select your files and then click on ‘Sign files’.

CHANGELOG :

03/05/2011 v1.1 :
- Add the "Change keys function",
- Works with ANDROIDD files,
- Some bugs are now fixed
18/03/2011 v1.1 :
- Add the drag and drop function
17/03/2011 v1.0 :
- Initial Release

Download v1.2 | here
Download v1.1

You can make new key with openssl command (just change NAME and PASSWORD):

openssl genrsa -3 -out NAME.pem 2048

openssl req -new -x509 -key NAME.pem -out NAME.x509.pem -days 10000 \
-subj "/C=US/ST=California/L=Mountain View/O=Android/OU=Android/CN=Android/emailAddress=android@android.com"

openssl pkcs8 -in NAME.pem -topk8 -outform DER -out NAME.pk8 -passout PASSWORD

via