Looks like it might work. Many of the apps want the LED or the flash which are only available on the iPhone 4. I saw one person who said the Haney app crashed after the July update. but in the iTunes reviews there's no info on what version of OS they're using. I am on 4.1 but the 3GS doesn't have all the bells and whistles the IP4 has which appears to make a big difference in the flashlight apps (except perhaps the one you recommended for which I thank you). All the others say iPhone 4 only!