This app can program AVR using the smart phone default bluetooth. You prepare the your target bootloader at the below the link. This version can write AVR full hexfile size. Bluetooth baudrate is 9600, n, 8, 1. Support and tested device: Atmega8, Atmega32, Atmega64, Atmega128. Updated hex for atmega64 - 2017. 04. 22. You can refer to.