Senior-Friendly VoIP Call-Blocking System

I'm seeking a developer to create a VoIP-based call-blocking system tailored for seniors using landlines. This system aims to protect them from spam calls while ensuring they can still receive calls from trusted contacts.

Key Features:
- Automated Message: All incoming calls are greeted with, "Hi, this number is protected from spam. Please press 7 to be connected." Calls not pressing the correct number will play an error message and disconnect.
- Unique VoIP Number: Each household needs a dedicated VoIP number. We will coordinate with their phone provider to forward landline calls to this number.
- Caller ID Recognition: Ability to recognize and manage calls based on caller ID.
- Whitelist Feature: Trusted numbers can be whitelisted to bypass the automated message.

Ideal Skills and Experience:
- Experience in developing VoIP applications
- Familiarity with call routing and handling
- Ability to create automated messages (pre-recorded)
- Knowledge of caller ID and whitelisting mechanisms

I work in the Medicare industry and see this as a valuable service for my clients, while also generating steady monthly income. I'm open to investing more to bring this idea to life. Your expertise in building this system would be greatly appreciated.