I found myself checking which skills my pets had a little too often, so I added them to the tooltip (and made sure you an hide them). I then realised that still didn't tell me when I could teach my pets a new skill, so I decided to log what skills my hunters know. This information is saved to the SavedVariables file when you open your training window.
Once this information is saved, PetInfoFu checks the level of your pet against the required level for the skill and adds it behind the pet skill. So a pet at level twenty, trained in Bite might show:
Bite Rank 3( 24)Grizzly UK
asked me to expand the way the addon shows itself on the FuBar and wanted to see the XP needed to gain the next level. After some fiddling, you can now show either the amount of XP needed to level or the percentage of XP needed to level.
His alternate option took a little longer, but you can now also show an estimated time to level. Basically you can (re)set the session (by CTRL-Clicking on the label) and it will do a rough calculation based on the amount of XP gained. If there's no XP gained when you start it shows 1D+
I also played a little with my Warlock and realised I have a skill problem there too. Any time she visits the Demon Trainer I have to figure out what skill all those demons currently cavorting in the Twisted Nether know, so as not to buy the same skill book twice.
PetInfoFu now keeps track of any skills your demon learns and will show those on the tool tip.