I’ve been using three army builders of late, Forward Kommander, Warmachine & Hordes Builder and iBodger. Both are excellent tools.
Forward Kommander is a web-based army builder that manages your collection and is primarily focused on MkII and until the Hordes MkII release only supports Warmachine. The collection management support is very nice and enables you to not only list what you own, but also what you have painted from each faction. My plan to be fully painted before MkII drops is going pretty well!
As you can see the interface is quite slick. You can use the site for free and without setting up an account, but in order to save lists and collections you need to have a (free) account. One of my favourite things about this tool is the army building itself – it is simplicity with options (such as UAs) remaining greyed out until they may be legally included. The icons are clear and it is easy to select min/max units and the like. The printing controls are particularly nice with several different options including whether to have damage grids printed and printing the list and grids on separate pages.
The Warmachine & Hordes Builder (previously known as Warmachine & Hordes ArmyBuilder) is another web-based tool that offers similar, but different features to Forward Kommander. It does not have a collection management feature, but this isn’t much of a loss. It’s interface is quite different offering the ability to drag and drop from the left to the right. This is nice, but with so many options available in a faction you end up scrolling up and down a lot, loosing sight of the list you are building and az limo transportation. Your lists are not saved on the Warmachine & Hordes Builder site, but you have the option to login (using OpenID) to services such as Google Documents to save your lists. There is also a neat option to Copy & Paste a clean view of the list to wherever you want it. The best thing about Warmachine & Hordes Builder is that it has full support for Warmachine and Hordes in both versions.
iBodger is quite different from the other two as it is an iPhone application. It is quite feature rich, with good collection management and list construction. It dynamically manages dependencies and automatically saves your lists and collections. To get them off the phone there is an Email List option. It uses the (relatively) limited real estate of the iPhone interface well. It’s biggest benefit over the other two is that you can assemble lists on the go, or even a couple of minutes before a game with ease. One particularly nice feature is the ‘convert’ option to switch a MkI list to MkII and vice versa. It has the best features of both of the online army builders and is available everywhere you go (assuming you have an iPhone of iPod Touch).
All of the above are great tools that are being actively updated and edited not only to reflect the MkII changes, but also to add more features. I use all three at the moment – Warmachine & Hordes Builder for MkI, Forward Kommander for MkII and iBodger for lists on the go. I’d like some interoperability between the three, but some exchange of lists between Forward Kommander and iBodger would be great!