MQTT-Based Software for Power Bank Rental

I need a skilled software developer who can create an application based on MQTT technology for my power bank rental hardware. The system's primary function is to facilitate the renting of power banks to users. The software must be compatible across multiple platforms including Android, iOS, and the Web.

Key Features:
- User Authentication: The software should have a secure and straightforward user authentication process.
- Rental Transaction Management: The system must effectively manage and track rental transactions.
- Real-time Power Bank Availability: Users should be able to see the real-time availability of power banks.
- Wallet-Based Payment System: The software should integrate a wallet-based payment system for seamless transactions.
- Integration with Paystack or OPay POS: The software needs to incorporate either Paystack or OPay POS for funding the user's wallet.
- Scan to Pay: A 'scan to pay' feature is necessary for convenience and efficiency.

Ideal Skills:
- Proficiency in MQTT technology
- Cross-platform software development
- Experience with secure user authentication systems
- Knowledge of rental transaction management systems
- Familiarity with real-time tracking systems
- Expertise in developing and integrating payment systems
- Experience with 'scan to pay' technology.

Please provide examples of relevant past projects with your bid.