Forcing users to pick from a short list of categories is frustrating. I don't think I will ever need to put passwords in a folder named password. I also would like to add a credit card to my finance folder, but cannot as you restrict the types of items that can be added to your predefined categories. It would be much simpler to allow users to create their own categories and add what passwords they would like to them.
Your current option of using a tag to organize your passwords is difficult, as you have to look back at what tags you have previously created to make sure you match the spelling exactly. There is no drop down list to choose from, so you constantly have to verify what tags you have previously setup.
Everyone organizes differently and allowing users to create their own categories would improve the overall app effectiveness.