As I'm sure everyone is well versed in the awesomeness that is Letterpress the app, if you're not, go download it here. Basically I fell in love with the super simple flat buttons and wanted to make something that people could use that was a little customizable. It looks pretty close in my opinion, but let me know if you have any problems.
Since this is just a regular button, you only need to set the title color for UIControlStateNormal and UIControlStateDisabled and everything is taken care of for you by the button class.
FlatPillButton by Brian Michel is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
Based on a work at https://github.com/brianmichel/flatpillbutton.
Feel free to contact me if you have any questions or issues, or send me a tweet @brianmichel. I've written a blog post regarding how I went about making this button here and would love a critique. Just go ahead and open an issue with the "Critique" label. Thanks!
Also, I can't stress enough, go download Letterpress because it's such an awesome game!