The VR5 pano viewer at http://www.vrhabitat.com/#vr5 should do what you need.
When you download it, you can test it out by importing the vr5_script folder into your Xcode project, making sure to check the "Create folder references for any added folders" option, then load it into the webview:
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:[
[NSBundle mainBundle] pathForResource:@"index" ofType:@"html"
inDirectory:@"vr5_script"]isDirectory:NO]]];
I just gave it a try and it seems to work quite well. Please consider donating to the author if you use it for commercial use (I am not affiliated with the author).