Imagine standing at the Eiffel Tower and being able to see messages and videos overlaid through your smartphone from all visitors who have come before you.

A new app called Wallit combines augmented reality, a virtual view of the real world that can be extended with graphics and other content, with a social experience.

It allows users to post and view content at virtual walls in popular places, tourist attractions such as the Eiffel Tower, stadiums and stores.

Think of a virtual wall on the face of the Golden Gate Bridge from one end to the other where people can leave sentiments, photos, movies and even audio that are persistent at that location, even though the people who generate the content constantly keep changing, said Veysel Berk, the founder of Wallit.

The goal, he said, is to record a cumulative, human experience at a location that exhibits the character of a place over time.

We wanted to move the physical experience of a public wall that everyone can see content on and move it into digital and virtual life, he explained.

To maintain the quality of content posted to the app users cannot create their own wall, which ensures there is only one wall for a place, producing a common experience for visitors. Content must also be generated and posted from the physical place where the virtual wall is located.

You cannot take a picture at the Eiffel Tower and then post it later to the wall at the Golden Gate Bridge. We make sure that all content is created genuinely at that location. That way we are pre-filtering the content and exhibiting the character of that place at any time, he said.

There are virtual walls available in all major cities worldwide.

In addition to providing a platform for users to contribute content, the company also sees virtual walls as a means for retailers to connect with consumers in real-time, and collect analytics on their customers.

There are 15,000 Starbucks locations all over the world. We are creating walls in each of these locations. If Starbucks claims and wants to customize these virtual walls we are going to allow them by subscription. They are going to be able to customize their logo, collect user feedback and deliver content to these walls, he said.

The company also plans to introduce advertisements to the walls.

The app is available for iOS, and will be launching for Android in the coming weeks.

(Reporting by Natasha Baker; editing by Patricia Reaney)