Apple has not yet announced the release date of its next mobile operating system, iOS 7, but some people can imagine the upcoming OS and show their creativity by posting a concept version of the OS.

Designer Fredrick Bianco posted a video concept of the iOS 7 on his Twitter account and his imagination looks very impressive.

In the concept video, Bianco has shown the iOS 7 becoming more user-friendly and more customizable, so the users can customize the lockscreen according to their needs and usage.

The lockscreen slider can have either the phone or the camera at the other end of the slider. To turn the Wi-Fi or the Airplane mode on, you don't have to go to the settings, it can be done from the lockscreen itself.

Tapping the available icons on the top panel of the lockscreen can change these settings quite conveniently.

The concept design of iOS 7 also makes replying and quick contacts very easy to reach. Other functions and widgets are also very easy to find and handle in the concept. The design also comes with a feature that closes all the open apps together without having to go to each and every app one by one.

Although the concept designs have started coming up for the iOS 7, Apple has not said anything about the release of iOS 7. Usually the Cupertino-based company releases every iOS during the Worldwide Developers Conference (WWDC) in the summer, but according to some reports, the development of iOS 7 is running behind schedule.

Prominent blogger John Gruber dropped a clear hint at the recently held Branch discussion and said, "What I've heard: iOS 7 is running behind, and engineers have been pulled from OS X 10.9 to work on it."

Watch the new conept video below: