The LocK-A-FoLdeR project has been abandoned which means that the developer won't provide support anymore for any of the inquiries (password forgot included).
The project is still hosted at the Code Google Archive, but I didn't find anything about it when it comes to resetting or recovering the password. The whole idea of these applications is to protect the data without any recovery options, that's why you have been probably notified to create a strong password and note it somewhre because recovery would be impossible.
