You can try to see whether it is stuck under your iTunes as pending downloads. Sometimes it happens. Check your iTunes purchase history under your account to be confirmed.
If you happen to come back to do more codes... I want to get snappy on my iPhone - This app looks really really nice. Would be very happy to review it. I've posted in case you decide to come back and throw out just a few more. If not , then good luck with your app!
My Review Camera Plus Pro- Ok I don't even know where to begin with this great app. It has everything the stock camera app should have had and i wouldn't be surprised if apple uses this app for their next iphone. It has an ability to take multiple pictures split seconds apart, It has built in zoom, a drop up menu that has so many cool features such as a button that lets you press any wheres to snap the picture for those moments of self portrait, ability to tag your pic with a name and date as ell as an ability to colorize the letters a built in photo storage and lock for those private pics you don't want seen on your camera roll as well as a built in sync of your photo's from the app to your photo roll which is really nice. There are other little nifty things added but i won't ruin it for those who like to find things out on their own but if your looking for a quality camera with a fast loading time on a 3GS this is the one. I tested it on my iphone and it loads just as fast as the one that came with the iphone. It even has a pretty nice Icon to go with it! Now the only negative thing i have to add which I do hope the developer can add (which i would love him for it) is if he can add the ability to switch from camera to video for the 3GS. I really would like to replace this app with the stock one, but with no switch to video (which I use all the time) I hate having 2 icons... Bottom line this app is everything you need for perfect photo capturing with the ability for some editing and an awsome icon. Don't be fooled by those other camera app, But this one instead. You won't be disappointed, I promise you!