Don't forget! Use Chromium on the linux machines, Edge on Windows and Chrome on chromebooks and Google Flex OS!
I was very pleased to find out that lists are available. Even more pleased that the make your own blocks feature includes blocks that return a value, i.e. functions, as well as 'procedures'. There are two different call blocks to distinquish between these two cases.
I tried out the making one's own blocks using the compass feature. There is a need to calibrate the compass before using it. There is a block which says to do this and the user helps by holding the microbit horizontally and tipping it to fill the screen. A message scrolls across the screen to tell you to do this. When all 25 LEDs are lit up the loaded program runs. My compass program indicated only North, East, South or West but all the same it worked. Very pleasing!