Quick install guide:

0) Install the dependencies:
It depends on argtable and libXpm. To install in Gentoo, do
emerge dev-libs/argtable x11-libs/libXpm

In Ubuntu, execute
sudo apt-get install libargtable2-0 libargtable2-dev libargtable2-docs libxpm-dev


1) Compile the project:
./configure --prefix=/usr
make
make install


2) Create the picture you are going to use:
a) get a picture of someone like your son or daughter.
b) crop a square containing his/her face.
c) resize-it so its 58x58 pixels.
d) save it in xpm format.

3) Run the application:
wmframepic -n augusto -f /path/to/xpm/file.xpm -d 23 -m 2 -y 2007

where
-n = name
-f = path to xpm file
-d = day of birth
-m = month of birth
-y = year of birth

when the dockapp is clicked, it will show how old your son/daughter is.

have fun!