Customizable Multi-Platform Auction App

I'm looking for a ready-made auction application that can be extensively customized to suit our company's needs. The application must support live bidding and include a user management system. It should be compatible with iOS, Android, and web browsers.

Ideal Skills and Experience:
- Experience in developing or customizing auction applications
- Proficiency in mobile and web application development
- Strong background in user management system integration
- Familiarity with live bidding functionalities
- Ability to provide extensive customization options