Quantity   Component name
1 × Teensy 3.2 (or 3.1) USB ARM development board https://www.pjrc.com/store/teensy32.html
1 × Adafruit Powerboost 500C 5V LiPo voltage regulator/charger https://www.adafruit.com/product/1944
1 × 3.7V 250mAH LiPo battery https://www.amazon.co.uk/gp/product/B01M3TP2X6/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
1 × 0.5W 15mm speaker https://www.rapidonline.com/Catalogue/Product/51-7389
1 × SPDT switch https://www.amazon.co.uk/gp/product/B06XSJLL9T/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
3 × Push buttons https://coolcomponents.co.uk/products/tactile-switch-buttons-6mm-slim-x-5-pack
1 × 2.2 inch SPI TFT display (240x320) pixels https://www.amazon.co.uk/gp/product/B0793NY1S7/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
1 × Set of 3D printed case parts Design files to follow.
1 × 15mm diameter key ring If you want to put it on a lanyard.
1 × Misc. items Small piece of stripboard, wires and solder.