At long last a sign of life from me.. after a week of extreme cold and a few days of snow storms here in this part of Germany, I'm going to open my repotting season this coming week.

I was wondering if you guys use any software to chronical what you do to your trees. I know a simple spreadsheet and some pictures etc will do the trick, but I was wondering if you had anything special you use.

thanks.

nop, spreadsheet, column per tree ( pictures, when repotted, pruned,wired, special events,...), page per year. Simple and effective , doesnt need to be anything more sofisticated.

Nope. I do not register when I do what.

I just like to take pictures when I do something, it's nice to see the progression in the future, helps to remember your bonsai history, the challenges it faced, changes you made... Soon as I see the pictures I remember what I've been doing on them, but I don't have many many trees...

I have done a spreadsheet in the past, as well as using an app to keep track.
Now I gave it up, and I photograph everything. As I use Lightroom, I keep track of the procedures by using the metadata embedded into the pictures, and keywords.
It works alright.