The repository contains a set of Espruino Apps for the P8 Smartwatch together with drivers to support these Apps. The following video demonstrates some of these:
This is very much based on the excellent Bangle.js and some Bangle apps and widgets require very little change to run on the P8.
For a brand-new P8, you need to follow the instructions here produced by @fanoush to get the right bootloader required by Espruino - SDK12 with Softdevice S132 3.0. After that you can flash the zip file from the firmware directory.
This build has a modified lcd_spi_unbuf module that works with SPI FLASH. The build makes the full 4 megabytes available to Espruino applications. In addition, there is a small hack to bluetooth to support the ANCS widget that connects to an iPhone.
Once Espruino is involved use the P8 App Loader to load Bootloader, Launcher and Settings followed by the apps and widgets you want.
To change Apps, a long touch on the touch screen will start the launch app. In addition, the P8 will display P8 Espruino when first booted and a long touch is required to start launch.
There is a distinct possibility of "bricking" your P8.
To mitigate this risk, boot sets a watchdog timer and if you press the button and hold it for over 5 seconds, the P8 should reboot when you release the button. If there is no response, let the battery go flat and the P8 should restart when you connect the charger.
Do not use clearWatch() anywhere as it kills both the button and the touch screen.
@ATC1441, reverse engineered the DaFit app and wrote DaFlasher which allows you to replace the firmware the P8 comes with.
@Fanoush, for the Espruino builds/bootloader and his help with getting the LCD driver to work.
@gfwilliams, for Espruino and for the Bangle App Loader used here. If you want a hassle free watch you can program off the shelf get a Bangle.js.