Accessibility side, Apple has added several elements, such as activating the flash of the camera for new notifications on the iPhone 4 or backplane dedicated to accessibility issues. Apple also proposes to change the behavior of the vibrator for calls only. Besides the continuous vibration by default, you can now choose between five vibration proposed by Apple, but also create new ones.
Apple has integrated the system with a vibration pattern generator custom. By tapping the screen, tells iOS when the buzzer is active. We can make a short tap or hold your finger to adjust the duration of vibration, while the intensity depends on the strength of tapping.
Other customization offered by Apple with iOS 5, the creation of custom gestures for use with "adaptive accessories. By default, a horizontal zigzag opens a menu, but the user can register new gestures. A priori, these actions will activate a specific function, but integration does not seem complete: once the action is recorded, IOS does not use it.
Since iOS 4.3, iPad used in development are entitled to a series of additional actions to manage the multitasking. Using four or five fingers can move from one application to another (shift to the left or right), show or hide the recent applications (sliding down or up) or quit an application by squeezing four or more fingers.
In the current beta version of IOS 5, these actions are available to all users and they are enabled by default. We can turn them off in the Settings, under "General", which will be useful for the (few) applications using more than three fingers at once.