Java Android Matrimonial App Code Upgrade

I'm starting a new enterprise and I'm looking for a skilled developer to help me upgrade an outdated Java Android matrimonial application with new, updated code. I need this to be done as soon as possible.

Key Requirements:
- Experience in Java, Android, and updating code
- Proven track record of successful app upgrades
- Ability to work quickly and efficiently

Please include details of your experience in your proposal. Thank you.