An accelerometer is a device that measures proper acceleration, the acceleration experienced relative to free fall. Single- and multi-axis models are available to detect magnitude and direction of the acceleration as a vector quantity, and can be used to sense orientation, vibration and shock. Micro-machined accelerometers are increasingly present in portable electronic devices and video game controllers, to detect the orientation of the device or provide for game input.
The iPhone comes with a nice accelerometer that permits the user interface rotation in certain apps and bringing forth the impressive landscape keyboard. There is no doubt that auto rotation is extremely useful, but it times sometimes becomes more of a nuisance for in a user who is caught in a constant portrait-landscape cycle. Sometime one would simply like to hold his device sideways to view something without the interface rotating, but it won’t stop from changing its alignment. Solutions such as SBSettings’ rotation add-on are available, but they change the overall settings throughout the device. How about having an application for specifically controlling the rotation?

The iPhone’s built-in accelerometer has created a world of opportunities for developers to create applications that are engaging, creative, innovative and fun. However, here is an App from EvilPenguin, The “INoRotate“, which when enabled, disables the screen rotation. The major difference between this one and the previous ones is that it allows for application specific control. Upon installation, it will add under the native Settings app. It will provide controls to disable rotation of All Applications, SMS app, Mail app, Safari app, Notes app and Contacts app.
InRotate can be found for free in Cydia via BigBoss repo.
Here are some screen shots on the use of this App:

iNoRotate2.jpeg
inrotate_iPhone_1-266x400.jpeg

[Via Funkyspacemonkey]