Unfortunately I got news a few days ago that Underscore Price Check was rejected by Apple for inclusion in the AppStore. The reason was that it uses some unpublished API:s to access the camera. I have since then rewritten it to not make use of those API:s and resubmitted it to Apple. Hopefully it will be approved now, but there will obviously be some delay before it will be available.
The good news is that the new version will also include some other improvements I have made including better performing scanning and support for Bing and iTunes search engines. Especially iTunes is really cool since it will allow you to listen to previews of records when viewing the results.