Assign location to photos

Useful new feature: add locations to photos based of the time of shot.

Suppose your photos don't have geolocation info, only time, and your track have time too. In this case you can automatically place your photos on the map in just a couple of clicks.

First, place one reference photo manually. This is needed to synchronize clocks between the track and the camera. After that, click "Assign Locations" button on top - all photos are now on the map.

If something goes wrong you can use the "Undo" button.

In other news, we fixed an important bug that prevented some tracks to display.