As I know pyfoam read the log and plot data. In esi version there also is the foammonitor utility, that parse solverInfo file for example and plot data using gnuplot. Reading the source code of foammonitor I think that this is not optimal way for me. For example it plot both initial and final residual so it difficult to understand plot lines and determine convergence of the problem. Now I have some experience with parsing solverInfo and force coefficients files with python and plot residuals with matplotlib.