Apex Launcher would fulfil your requirements. Im using it for quite a while now, and am very satisfied with it. In its configuration, you can define whether it should support rotation, or alternatively fix it to either portrait or landscape mode.
Apart from that, even in its free version (the one I've linked), the feature list is impressive:
• Customizable homescreen grid size and up to 9 homescreens
• Scrollable dock with up to 7 icons per page and up to 5 pages
• Infinite & elastic scrolling (homescreen, drawer and dock)
• Fancy transition effects (tablet, cube, etc.)
• Hide elements as you want (persistent search bar, status bar, or even the dock)
• Customizable icons and labels for shortcuts and folders
• Choose different folder preview styles and background
• Multiple drawer styles (transparent/opaque, horizontal/vertical, paginated/continuous)
• Drawer apps sorting (title, install date, mostly used)
• Hide apps from the drawer
• Lock your desktop to prevent accidental changes
• Enjoy homescreen gestures (pinch, swipe up/down, double tap)
• Advanced theme engine (icon packs, skins, etc.)
• Backup/restore settings and data
• Optimized for both phones and tablets
• Lots of other customization options!
Runs stable, never caused me any issues. Using it on most of my Android devices (Android versions 4.0 and 4.1).