The online gallery is made up of 100 panoramic images taken from various points in and around the medieval section of the capital.
While touring the exhibit's many outdoor sights, internet visitors can view the city skyline from numerous towers, get to know the Old Town streets and "scroll" around in Tallinn parks.
The exhibition also includes indoor sightseeing, letting visitors take a sneak peek inside the 15th-century Town Hall, historic churches and other buildings.
Development of the photo application, which works in Estonian, English and Russian, was funded by the European Union.
A separate project that's expected to be launched in the near future will offer a three-dimensional virtual representation of Old Town, the capital's newspaper Pealinn reported.