This review originally appeared within iLounge’s iOS Gems series within the compilation article, iPhone Gems: All 22 Wallet Apps, Reviewed. Additional details may be found in the original article.
NotePadLock ($2) is a secure note storage application that almost falls into an entirely different category from the other apps we’ve looked at, but is included here as it is a general-purpose secure storage app. Rather than taking the approach of a single password that opens up the entire database, NotePadLock uses a six-digit code as its filing system.

You basically create a note with a title and text, and then lock it down with a six-digit code. You then use that particular code to retrieve or edit that particular note. If you want to create another note, you simply secure it with a different code.
You can re-save an existing note with the same code by tapping on the padlock, or change the code by tapping on a key icon that appears after editing an existing note. No master database or index of notes is provided. If you create a note with a given code and then forget that code, you will basically forget that this note even existed.