Doppelganger 1.0.5 could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this software available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The actual developer of the software is Platinum East Ltd. The software lies within System Utilities, more precisely File Managers.
From the developer:
Simple to use yet powerful utility for performing unattended timed backups of important files and folders to a second hard drive, removable drive (e.g. Zip Drive) or network drive. Supports multi-user, multi-workstation operation. Saves time by only backing up those files that have changed since theprevious backup. Provides logging facilities, explorer style file and folder selection and clean-up facility for backup maintenance.
You may want to check out more software, such as Stranded Dreamscapes The Doppelganger Collectors Edition or Stranded Dreamscapes The Doppelganger, which might be similar to Doppelganger.