iOS7 transition guide (UI): https://developer.apple.com/library/ios/documentation/userexperience/conceptual/TransitionGuide/index.html

iOS7 std link problem:  found linking problem (only) on iOS7 , solution is to add libsstdc++ manually into the build phase – link as described here: http://stackoverflow.com/questions/18959691/ios7-only-stdlibc-linking-issue

Fix UI controller layout for iOS6 and iOS7:

http://www.mobinett.com/2013/08/19/ios7-ui-transition-porting-view-controller-layouts-ios6/

// -- hide status bar on iOS7  - add to controller:
 - (BOOL)prefersStatusBarHidden{
 return YES;
 }

-- not iOS7 related but useful: create cell view either from Nib or manually:
 //-----------------------------------------------------------
 -(CategoryCell*) createCell{
  static NSString *reuseId = @"CategoryCellIdentifier";
  CategoryCell *cell = [self.tableView dequeueReusableCellWithIdentifier:reuseId];
  if (cell == nil){
   cell =  [[UINib nibWithNibName:@"" bundle:nil] instantiateWithOwner:nil options:nil][0];
 //cell = [[CategoryCell alloc] initWithStyle:UITableViewCellStyleSubtitle  reuseIdentifier:reuseId] ;
  }
 return cell;
}