In the past few days I have been further researching sensors to be used with the Pi Portable Recorder and I am currently making a breakout board which will contain them all (for easy prototyping). The first sensor are a BNO005 9-axis absolute orientation sensor which contains an accelerometer, magnetometer and a gyroscope as well as a 32-bit cortex M0+ microcontroller which processes all the sensor data using Bosch's sensor fusion software before passing on the data to the Pi. I am also using a BMP388, an accurate pressure sensor which can be used to work out altitude to within around half a meter. I am also using an SHT35-D chip to measure temperature and humidity. This is also super accurate (maybe too accurate for my usecase =D) to within 1.5% relative humidity and within 0.1°C. It is likely the sensors used will change again, probably due to space constraints, but I at least plan to make and tests a breakout with all of these sensors.

As well as hardware, I have started developing my first Pi Portable Recorder app. As I have not got the hardware to create and test a recording app yet, I have been working on an app to create bird lists. This will allow the user to manage lots of lists (patch lists, year lists, day lists, life lists etc.) through menus and add new items to the lists as well as information about them (dates, locations and notes), search the lists for items and of course create new lists. These lists are saved as csv files and opened by the built in csv python library. I have currently created the basic app, added the ability to open the csv file for editing and reading (and put the data into Python lists) and added the search feature. I just need to add the feature of creating and adding to lists as well as making the UI more user friendly before I commit the app to the GitHub page (in the devel branch) - https://github.com/LouisPi/piportablerecorder/tree/devel. 

Meanwhile, if anyone has any suggestions or comments regarding the Pi Portable Recorder please do start a discussion on Hackaday.