Android VoIP Calling & Texting App

I'm looking for a skilled developer to build a comprehensive VoIP calling and texting app for Android. The app should support real phone numbers and include the following features:

- Voice calling
- Text messaging
- Voicemail
- Picture and video messaging
- Accepting short codes/verification codes/ 2fa
via text

The user authentication for the app should be simple and secure, requiring only an email and password for login.

Ideal skills and experience include:
- Proficient in Android app development
- Experience in building VoIP applications
- Understanding of user authentication systems
- Ability to integrate multimedia messaging
- Knowledge of handling SMS short codes

Freelancers with a portfolio of similar projects will be highly considered. I look forward to your proposals.