I need a Java App developer for Android

General information for the business: Race Engine Electronics
Kind of development: New program from scratch
Description of requirements/functionality: Basic overview
This project/App is for automotive use; reading RPM, speed, throttle etc
Wired to the vehicle is a hardware unit with a Bluetooth module in ( already developed )
The app reads a collection of bytes in a data-stream from the Bluetooth on the android phone, displays and saves it to SD card.

More detailed description
The app reads every 10mS a packet of bytes from the Bluetooth module. This is unpacked and a simple set of error checks are performed, check sum header footer checks etc
It converts the bytes in the packet into about 10 16bit numbers. Then with simple maths we will need to convert the numbers into scaled values using a user settings value/s
ie one number is the time between wheel sensor pulses this has a settings number for pulses per wheel rev and tyre circumference to finally generate a value of Kph.
Some of the data is displayed on the Main screen: Lap time, Lap number etc
All of the maths converted numbers are then stored onto the memory card.
The 3 activities (screens) are:
• Main screen with a large display of lap time and lap
• Bluetooth paired device selection listbox screen
• Settings screen were the user and change the settings (maths values) and also see the current value ie RPM, Speed etc, these setting can also be saved and retrieved.

The background services are:
• Data storage to memory
• GPS geo-fence detection of start line location
• If available on the phone a G-force sensor and or gyro read and simply save this data to memory with the other data

Memory
Memory service, saves the ‘log’ data to file on the SD card storing the date and time with the file.
When the RPM stops for longer than 5 seconds the file is closed. On RPM starting again a new file is started
If the memory is getting low then the service needs to delete the oldest ‘log’ file stored on the card. Memory use is about 2Mb per hour
GPS - laptime
The start line / lap detection will be done by two methods : a hardwired sensor , the Bluetooth module will just pass the time in the data stream or ( user selectable ) by GPS
With the GPS some maths will be needed to locate the passing of the start line in windows phone this could be done by geo-fencing I not sure on Android what the best method would be
The hardware
The Bluetooth unit has commands to stop stream, start stream, reset etc. This unit is designed but can be changed if we feel that a new command or feature is needed.
Current progress
I have some software skills and a simple version of the Bluetooth comms has been played with on windows phone 8.1 visual studio and proved that it works. I did start to learn the android SDK / java / xml but I’m old school and will stick with programming small chips in assembler!
I have the ability to test this at race tracks as we need it to work at speed!
I will want to upgrade this in the future and also bring this out on Windows phone too at some point, small steps first.

The Applicant
You must have published apps for android before, and be able to provide samples of work.
• I’m based in Nottingham in the UK but the project can be done anywhere. A Hardware module with some fake inputs can easily be posted out to test the system
Specific technologies required: Java on Android
Extra notes: