The trace_irc code described in Ref.  can be downloaded from this GitHub page.
The program can read metadynamics output files from CPMD, CP2K, and PLUMED and trace the lowest free energy pathway. A brief description is found in a README file and a list of the keywords is generate by running trace_irc.x -help. There is no manual unfortunately. In case you wish to addapt the program to read your favorite input, this should not be so hard, as the C code is commented and not difficult to read. Good luck playing with it.
 A recipe for the computation of the free energy barrier and lowest free energy path of concerted reactions. Bernd Ensing, Alessandro Laio, Michele Parrinello and Michael L. Klein, J. Phys. Chem. B 109 (2005), 6676-6687 DOI: 10.1021/jp045571i
 Perspective on the reactions between F– and CH3CH2F: the free energy landscape of the E2 and SN2 reaction channels. Bernd Ensing and Michael L. Klein, Proc. Natl. Acad. Sci., USA 102 (2005), 6755-6759 DOI: 10.1073/pnas.0408094102
 Metadynamics as a tool for exploring the free energy landscape of chemical reactions. Bernd Ensing, Marco De Vivo, Zhiwei Liu, Preston Moore, and Michael L. Klein, Acc. Chem. Res. 39 (2006), 73-81 DOI: 10.1021/ar040198i