The Combonator is a study tool for Hold'em games to count combinations and analyse ranges.
To understand exactly what that means, you can see a screenshot and watch a short introductory screencast on the homepage:
http://combonator.com
If you can't stand 8 minutes of a British accent, I suggest you just go ahead and download it, there's a short 4-page presentation when you load the program:
http://combonator.com/download/
I would recommend you either read it or watch the screencast because parts of the interface are unique to the program and things might be a bit confusing at first.
The Combonator has been out a while now and is used by a small group of users. I've finally finished a 3-part tutorial and put more information up on the website, so I thought it time I started to announce it publicly. If you want to learn more, the tutorial is up here:
http://combonator.com/help/
If you are an old v1.0 user or beta tester, you may not realise that version 1.1 is out with a bunch of improvements to the outputs tab. You can learn more on the blog here:
http://blog.combonator.com/31204374
The project first started out as just a tool for personal use, to fill the gap left by the demise of Stoxcombo (whilst fixing some of the bugs and a more intuitive take on the interface). But since then it's grown in to a much broader bag of tricks for looking at opponents ranges and balancing your own range, and board texture analysis (a la flopzilla).
The program is free to use, but there is a paid 'pro' version that unlocks a couple of features. I wanted to make sure the tool is is fully functional and useful in the free vanilla form, so there's no time limit, no nag screen. I hope in v1.2 to expand the feature set of the pro version significantly.