I would like a program where you input a desired edgework configuration, and it outputs the seed(s) that would produce that configuration. Ideally, this would function similarly to the edgework configuration feature in the test harness. The program could allow you to leave certain pieces unspecified to keep generations options opens. For example, if you want a CAR indicator present, you can have an option for not care if it's lit or not.
This would be useful for testing unicorns in the game without having to download or modify the source code. Given the number of configurable options (a lot more if you count modded widgets), this might work best as an external program, though it could theoretically be implemented as a holdable.
The program can also do the inverse in which you give it a seed and it tells you want widgets will appear on the bomb. Though that may work best if program is external as you can just run the seed in game to get the same results.