Need architecture direction

I'm creating an app and I need some help with design.

Launch Screen - I want to show 6-8 "category" buttons with labels loaded from an array ("normal" buttons from interface builder - not tab bar buttons or menu bar buttons). Table Screen - When one of the category buttons is pushed on the launch screen, I want to show a table view with all of the items in that category. Detail Screen - When one of the items on the table screen is selected, go to a new screen with details for the item. There will be an action button on this screen which will remove the item from the list if pressed.

My questions are as follows:

1) I don't want to show navigation buttons on the first screen. Can I still use a Navigation-Based application and hide the navigation controls on the first screen, or would it be better (easier) to create a view-based application and put a navigation controller "inside" one of the views? I'm totally open to any basic design approach suggestions you may have.

2) I've figured out how to create a sqlite3 file, add it to the project, query it, and generate the table view from the results, but I'm not sure about how to store the sqlite file in a way that will per开发者_如何学Csist on the device when the user upgrades the app later. Any pointers on that?

Thanks for any help/links/documentation you can point me to. I've watched a million tutorials but none of the ones I've seen really address basic app design.

---

Now for Q1, both ways work fine but if you have buttons from the first screen, having a uinavigationcontroller might make it slightly easier if you plan to have back buttons on the screens after the first screen.

For Q2, to make the database persist when the user updates their app at some stage, simply keep the original database and include a new database (with a different name) with additional content, then modify your original database and import any additional content to it.

You can also do variations of that also, ie import content from old database to new database and etc. But the key is to keep the database file names different, ie add database_v1.sqlite, database_v2.sqlite and etc.

BTW don't forget to clean up any databases you won't use in future.