Actually, it appears I have a defective phone. Just received my white Lumia Icon today. Rolled back to Windows 8.0 with Nokia's rollback tool, and no apps rotate when I rotate the phones. Perhaps the sensor that detects rotation is defective? I know other Windows 8 phones rotated some apps. And I confirmed that rotation lock is not enabled. Frustrating, but it seems I may have a phone issue. Are there any apps out there that test sensors?