Interesting discovery, this - looks like a French developer has produced a kind of ultra-simple spreadsheet that specialises in hierarchical layouts. Bloody good idea! I'm just testing out the trial edition, I'll let you know how I get on. You'll find it at:

http://www.aflava.com/

My favourite ultra-simple spreadsheet at the moment is the one included in AM-Notebook, which supports rich-text notes and mini-spreadsheets in its outliner (it also does tasks and contacts reasonably well). I've been impressed enough by AM-Notebook to purchase the Pro version. You'll find it here:

http://www.aignes.com/

(This is the same guy who produces the wonderful Local Website Archive and Website Watcher - the former free, the latter to buy. AM-Notebook Pro integrates with Local Website Archive, so you access - and view - your offline web pages directly from AM-Notebook Pro - not from the free version, unfortunately, although Local Website Archive is available as a permanently free standalone.)

I tried pasting in an indented text file and all it would accept is the first line. I'd need to see some sort of import capability before buying it. TreeSheets manages this wonderfully.

Yes, sadly it's currently fairly dreadful. And doesn't have a Search or Find function, which to my mind makes it outrageous that he's trying to sell the thing...