To get to the Holiday Lights! Web App go to: http://digistump.com/holiday
Select the board you want to create a program for - do this first because any changes will be lost if you switch.
Each board can have three scenes loaded.
A scene is a sequence of up to 13 colors for each LED. Each scene can have its own setting for how the LEDs change between colors (different time amounts or by button) and what to do when the end of the longest sequence in that scene is reached (repeat, stop, go to next scene).
You can only edit the second scene after creating something in the first, likewise for the second to third. You can switch between scenes in the app without losing your work.
At the bottom of the web app you'll find various option menus.
Scene Settings: Discussed in the last section.
Main Settings: Select whether a button starts/stops the program or if it just starts at power up. Select whether a button changes scenes.
Download: Download the one click installer for your platform, or the sketch to use in the Arduino IDE (see Holiday Lights! with the Arduino IDE)
Click on an LED to set the sequence of colors for that LED and the visual effect the LED uses.
Hit the download button and select your platform. Unzip or untar the file that is downloaded and run the “upload” script in the folder by double clicking or running it from the command line (from the same directory it is in).
DO NOT plug in your Digispark until it tells you to.
It will say to plug in your Digispark - do so when it says this and it should program. You can leave the Digispark attached to the Holiday Lights Kit or remove it - just ensure no batteries are in the kit if it is attached.
Once programmed reattach it to the kit (if you removed it) and power it on - after 5 seconds of all the LEDs being blue it will start your program.
For troubleshooting with the programming see here: Getting Started with your Digispark or Digispark Pro
Do NOT run the kit from USB power when batteries are inserted. It will not harm your computer/power source but it may harm the batteries.
If you are using the option to have a button turn it on and off and powering from batteries, remove the batteries when not in use - it is not a low power device and it will deplete the batteries after a day or so in off mode. This was not originally planned as a feature which is why it has this limitation.
In the Web App, even if you are going to use a button to change colors, then click on that button on the image in the web app, and it should work as it would on the device. Button use for on/off is not emulated.