Sometimes an otherwise useful application is missing a feature or two. Take the Stickies app, for example. For whatever reason, the authors decided not to include a scrollbar. Perhaps this was because it’s not a necessary feature for most users. Perhaps it was just overlooked.
Thankfully, you can customize most OS X apps with the tools that come with the Xcode dev suite. This goes beyond mere skinning. You can actually add functionality that wasn’t part of the application’s original design! Erica Sadun, author of Modding Mac OS X, writes:
Not only can Mac enthusiasts modify an application’s look, but we can also actually change the way it works. OS X’s Interface Builder, part of its Xcode development suite, provides all the tools you need to go beyond. With Interface Builder, you can accomplish the unthinkable. It lets you customize existing applications in ways that ResEdit users never dreamed of. If you think that customizing an application interface involves nothing more than moving a button into a new position or resizing a screen, think again.
In Erica’s howto, she heavily modifies Stickies, adding a ruler toolbar, a drawer containing extra preference and utility options, and the aforementioned scrollbar. You can use these same tricks to alter your other favorite Mac apps… just make sure to give us a shout with your own slick application mods.
Modifying Stickies –Link.