Rotation lock is a useful feature, until it gets in the way. For example, reading on the iPhone can be easier with the lock enabled, to prevent everything from spinning around when you lie down. The problem happens when rotation is locked, and you’re trying to watch a widescreen video.
Your iPhone is forced to display this video in the vertical orientation, making the picture incredibly small with large black letterboxing at the top and bottom of the display. Fixing this involves switching off rotation lock then rotating the iPhone and restarting the video. The LandscapeVideo tweak makes this process easier on jailbroken devices.
In fact, LandscapeVideo does all of the work for you. When enabled, the tweak will automatically turn your video into landscape mode without switching off rotation lock. There are some settings with the tweak, including whether to enable LandscapeVideo all the time, or just when rotation lock is on. You can also choose to limit landscape display mode to the home button on the right, left or allow both directions.
LandscapeVideos is available on Cydia from the ModMyi repo free of charge. Check here for instructions on how to jailbreak iOS 6.x with evasi0n. You can also find out how to purchase and install Cydia tweaks with this guide.