You can blend the results of any two of the 35 preset effects with the original picture. (screen capture reduced from true size)
For image manipulation tools there is the Paint Tools window shown below.
Tools include: tinting sharpen smooth replace a color saturation brightness and others. There are brushes for clone smooth lighten darken pen and watercolor. Colors can be set with an eyedropper from the picture with sliders clicking the "W" or "B" for black or white and you can save a color for use later or even after closing and restarting the program.
Notice the "Trace" button and the 3 buttons below it. These allow you to trace the picture with the magnifier assisting if you need it. The tracing is assisted by the program which searches out the widest line near where you move the cursor.
ZenLiner has a window for creating signatures which can be saved and applied to any picture also in this window. When you're ready to sign just pick one from those you've created here and drop it on the picture where you want it.