Beaten to the punch on one iPhone App idea

I've got three ideas for iPhone Apps that I'd like to try. Up until a few weeks ago, no one had done any of them. Then I discovered the "CardStar" App which is right in line with one of them. CardStar lets you punch in the numbers under the bar codes from various membership, V.I.P. and reward cards and then recreates the bar codes themselves on the screen. The idea being that you can store as many as you want in your iPhone/iPod Touch and leave the actual cards at home. With all the other stuff I carry around, anything that can keep me from having to take something else along is great. So, the idea of CardStar is awesome. I've only been using it for a little while and have run into a few issues. First off, some scanners have a hard time with reading the barcode on the screen and some simply can't do it. This isn't CardStar's fault. Just an issue between the way the two technologies work. CardStar's FAQ recommends having the merchant use their handheld scanners instead of the flatbed ones. I've seen this in action at my local Winn-Dixie. The flatbed didn't work at all, but the handheld was able to pick up the bar code. Sadly, some handhelds don't seem to be able to pick up the bar codes either. A second issue I've run into is that some places won't let you use anything other than the original card. I'm guessing most grocery, drug and retail stores don't care, but my local library does. Once again, not CardStar's fault. Just the way things work. There are some changes I'd make to the User Interface of CardStar to make it more intuitive, but all it all, it's a good little app. For the time being, it's also free. If you have an iPhone or iPod Touch, go pick it up and give it a try.