Installation should work the standard way

1.) unzip tarball
2.) open a shell and cd to topmost directory of project (where the configure script resides)
3.) execute configure script: ./configure (you may have to install the development libraries of wxWidgets to successfully run configure).
4.) execute make: make
optional: 5.) on success the binary appears in the project directory, execute it and explore the local version using the local configureation. 
optional: 6) if you have a prior installation of academic signature, save the present keyfiles and configuration (the ~/.config/aca_sig/x_secrets and key_tray directories) to a safe place for later restoration.
7.) execute: sudo make install (on a debian/ubuntu) to install the binary and the virgin configuration files
optional: 8.) restore the saved prior x_secrets and key_tray folders to ~/.conf/aca_sig/ to retain the old keyring, configuration and access passphrase. If you forgot to save them, you may find a backup of x_secrets in the folder x_secrets_bak ;-)
9.) Place a menu entry and/or a panel icon at an appropriate place and configure it to run aca_sig from the home directory ~/  - you may use the icons shipped with the tarball (topmost directory in tarball and/or copied to ~/ on install).
