Hi m.wenglar,
Currently the only option we have available for this is the title. In the edit file menu you can change a one line title. Is this enough room for your notes? If not, then you would have to export a picture and use paint or some other similar program to add text. I do have this feature request from another user, I’ll add your name to it. It’s interesting and something we can consider adding to a future version of Spike. I can’t make any guarantees on when.
As an alternative, if you are using Windows, you can use the snip n sketch tool to take a screen shot then from within that app open the screen shot in paint to add your text. There are also 3rd party windows applications that have this functionality (annotate a screenshot) all in one. I personally haven’t used any of them.
Regards,
Andrew