Sketch is a Software by Sony.
You can install it on your android mobile.
Sketching used to be a great pastime for me during my school days.
After school life my area of interests grew. I spent a lot of time learning new things like I learned flash ( used for animations and games). I learn programming and endless softwares and tools.
Did not got time for sketches. Without any plan I searched for a drawing app and found sketch by Sony.
The tool is quite easy yet powerful. I loved it. Here are a few things I drew.
Paintings on Wall 
Face 
Water Bottle