You will need to install libgtk version 3.0 (for libgtk-3.so.0) and libdbus-glib version 1.2 (for libdbus-glib-1.so.2). These may already be installed on your distribution if you use Ubuntu or Fedora. If you have Firefox installed, then you already have these shared libraries.
A simple way to get setup on most Linux distributions is to first install Firefox which will install the necessary dependencies. After that, it should be easy to download Replay and get started.
Check out our Linux Support guide for more details.