Build cross-platform app for audio processing

We have a sensor connecting to phone charging port and pass in readings as audio signal. Looking for a mobile developer to create a cross-platform app for the sensor.

Major tasks/requirements
1. Cross-platform app for both iOS and Android
2. Create software interface. We will provide interface design
3. Interface should be responsive for different devices
4. Read incoming sensor readings as audio signal, we will provide algorithm for further signal processing
5. Show sensor readings in a plot with basic zoom and pan enabled
6. Allow user to save recorded data in local database
7. Create a data manager to allow user to view previously saved records
8. Allow user to export sensor readings as CSV or WAV
9. Create a user management and subscription structure to charge user monthly

Please send a proposal in doc/pdf answering the following questions:
1. Your hourly rate
2. Your available hour per week
3. Link 3-5 of your best related work samples
4. The development tool/framework/library you will use
5. How long have you been working in mobile app development
6. Are you working individually or under a company
7. Do you have any coding related degree, if so list it
8. List your strong skills in mobile app development
9. Rate your English level from 0 to 10
10. Will you be available for weekly online audio/video meeting
11. Do you have development experience with other platforms

YOU MUST ANSWER ALL THE QUESTIONS IN ORDER TO BE CONSIDERED FOR THIS PROJECT.