Hey, finally time for an update. Firstly, I have just finished a basic bird list app which can be found here - https://github.com/LouisPi/piportablerecorder/blob/devel/apps/ppr_gui/bird_lists/main.py. It is far from perfect but finally all features are at least working. For development purposes input is still taken from a normal keyboard and some text is still output on my monitor. This should change as I will be receiving a Zerophone soon which has all the hardware required for testing my apps as well of course being a oober cool Pi Zero phone. 

Also, I have finished a basic pre amp for the electret microphone using a TLC272. This is an old chip but from what I have heard and read it is still a decent op amp. The easyeda project for this can be seen here - https://easyeda.com/granbobbi22/mini-pre-amp and a picture of the PCB can be seen below. Note - the TLC272 supports two input and outputs and a future version will be made to support two electret mics.

Unfortunately, the Pi Zero version of this audio board I found is on hold as I investigate why the the schematic file isn't loading =(. I have also put the Super Sensor Breakout on hold as I have sensibly decided that sensors will probably not fit and are definitely not the priorities of my project right now. Some good news is that I have a schematic for a MP2636 based lipo/li-ion booster for the project finished and am now in the process of developing a PCB for it.

Meanwhile, if you have any question of course just ask in the comments.

P.S - A more detailed PMIC log is planned with info on the MP2636 and the AXP209.