I used the free Lego movie app on the iPad to create the film, but then had problems uploading it to the blog. I couldn't use the Blogger app to add it as there is no video upload option, so I switched to the web version of Blogger (still on the iPad)... but you can only upload video from Google+ or You Tube (not from the camera roll, where it was saved) - there is no file structure on the iPad so you can't navigate to where things are saved as you can on a computer.
So, Plan B: I signed up for Google+, downloaded the Google+ app to the iPad and should then have been able to add the video by using the clapperboard option on the blog toolbar. However, because the video was saved as a photo in Google+ it couldn't find it as a video (I couldn't see a way of changing it), and if I loaded it as a photo it didn't appear in the blog. Grrr.
Now we're on to Plan C; I added the video to Dropbox and am now writing this on the old and clunky laptop that objects to, well, doing most things. I think I have managed to upload the video though (using the clapperboard on the blog toolbar then navigating to find the video in Dropbox), so thank you computer. And thank you Mr Conehead for sharing your day with us: