ShiftCycle
About a week ago, I noticed that someone had posted on the subreddit /r/Jailbreak asking for a tweak. What it did was make it so when you selected text, and clicked shift, it would toggle the text through UPPERCASE, lowercase, and the original text. I thought I could make it, and within a few days it was working great. The source code is up on my GitHub if you want to check it out.
If you want to install it, simply add my repo, http://cydia.alexbeals.com, and install ShiftCycle, or you can download it from BigBoss.
Where the story of this tweak diverges from PasscodeActivator, is that it was the first tweak I'd released on BigBoss. Within one day of releasing it, it was posted about on iDownloadBlog, tweeted about, and two people sent in a total of $15 as a donation. You can check out the download stats here, but as of writing it has over 1500 downloads.