The first step is to double click on a thumbnail to open the editing options. Several tools for editing and some filters are provided. Among the several buttons, you shall get the following:
Crop: to make a cut in the picture.
Straighten: a slightly recovers inclined image.
Red eyes: correct the well known flash effect on the human eye.
I'm lucky: this button enhances dark colors and clear colors. This also optimizes color and contrast. Auto Contrast: optimize brightness and contrast with one click.
Auto Color: shades of color are cleared and balance is restored.
Lighting: move the cursor on the slider to add light to the first plan.
The Cancel button removes one by one changes applied. The Settings tab contains several sliders to change the lights, shadows and color temperature. Finally, the Effects tab offers several filters such as Sepia mode or artistic blur.
To validate a modification, just click on Store option found in the lower panel.