Q:

More than one tab bar in an app?

I have developed an app that has work successfully for the last 4 months using iOS 4.3 and under. Since iOS 5 however the tightening of view hierarchy has left my app dead in the water. The app starts with a tab bar as its main view with 5 tabs. When the user selects a row on a tableview on the first tab it pushes onto another tabbar with 3 tabs which gives specific information about that selection. This structure worked fine but obviously broke when testing on iOS 5.
My question is: Is it bad design to utilize 2 or more tab bars in one application? I don't mean "bad design" in the grand scheme of things because that is subjective. I mean in a practical sense where it is specifically forbidden or not recommended.

A:

have a look at this:
iOs Human Interface Guideline
Yes, I think that it's not recommended.
For example:

Use a tab bar to give users access to different perspectives on the same set of data or different subtasks related to the overall function of your app. When you use a tab bar, follow these guidelines:
Don’t use a tab bar to give users controls that act on elements in the current mode or screen. If you need to provide controls for your users, use a toolbar instead (for usage guidelines, see “Toolbar”).
In general, use a tab bar to organize information at the application level. A tab bar is well-suited for use in the main app view because it’s a good way to flatten your information hierarchy and provide access to several peer information categories or modes at one time.

