WebODM 2.5.5 was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this software available. WebODM relates to Photo & Graphics Tools. This free program was originally created by UAV4GEO. We recommend checking the downloaded files with any free antivirus.
From the developer:
User-friendly, commercial-grade software for processing aerial imagery. Generate georeferenced maps, point clouds, elevation models and textured 3D models from aerial images. It supports multiple engines for processing, currently ODM and MicMac. WebODM can be linked to one or more processing nodes that speak the NodeODM API, such as NodeODM, NodeMICMAC or ClusterODM.
You may want to check out more software, such as Panorama Maker, Focusviewer or Poster Buddy, which might be similar to WebODM.