Using the AIMS (Autodesk Infrastructure Map Server) Mobile Viewer on an mobile phone / tablet it is not possible to zoom out of the map with your fingers.
The tool only allows to zoom in. The only function in the Mobile Viewer is the overview button (in the screenshot "Anfangsansicht") in the menu. However, clicking this button the user returns to the whole overview map. The user loses the location he/she zoomed in and is interested in.
To make this tool more user friendly it would be great to implement a zooming out function within this tool for users using mobile phones / tablet.