One of the features I've been looking to develop for TTORP character sheets is something I've been calling "layers."
Disclaimer: this might not be applicable to every type of character sheet out there, but I know it will apply quite nicely to Dungeons & Dragons 3.5, and probably other editions as well.
So imagine creating a character. It's a human, 18 years old, blah blah blah. Now you add your first class level, like ranger. That comes with all kinds of special abilities, skills, etc. And every so often, that character gets a new level, and the same process happens again.
Wouldn't it be cool if you could separate out the changes for every level? So you and your DM could see exactly what changed on the 3rd level of ranger?
One of my players really likes to create a character and figure out what all their levels are going to look like up to a certain point. The character sheet can only show the "here and now" version, so he has to put it into a spreadsheet somewhere.
With layers, he could create all those levels ahead of time. And whenever we're playing, just untick the layers that aren't applicable, so it shows that the character is 3rd level.
With each new level, he just checkmarks the appropriate level, and he's done. If he ever wants to reconfigure his character, he can do so really easily just by fiddling with the levels by adding, deleting, and modifying them as necessary. When it comes time to ask me if I'm okay with the character build, he can just apply all the layers, and I can look at the end result, and even pick apart each layer to see what he's done!
So let's say you've got a character, and you want to add a level as a rogue. How cool would it be to just click a button to add a pre-build layer that represents that rogue level? Maybe some prompts that ask how you wanna spend some skill points, and some other things?
I'll answer for you: it would be AWESOME. That's the power of layers.
What if your character becomes an afflicted were-creature? There's a template for it... which normally pretty much requires keping a second character sheet updated. Every new level requires updating two character sheets. And for a shape-changer, that can have a whole bunch of templates? Crap.
BUT WITH LAYERS, each of those templates is just a layer. And it doesn't have to be updated because the layer just modifies what's already there. Simple and awesome.
I've discussed this concept with my software developer friends, who are also TTORP fanatics as well as players (DM's), and there are even more possibilities. A DM could add a layer that pertains to a specific battle, which has a series of effects on attributes and such. Once they're done, the DM can just delete (or de-activate) that layer.