I've bought the full version of Colors! by Collecting Smiles and it's ran wonderfully for me. Pretty simple interface, as well as having support for touch/pressure sensitivity. Pressure/touch sensitivity support is not best on my particular device (SGH-I777), so I leave those settings off most of the time. I still use my capacitive stylus with it to doodle things, even my index finger sometimes, so that's not a major problem. :P Collecting Smiles also made another version for Galaxy Note devices, though I've heard the original version is better. If you'd like to give it a try, here are some Google Play links:

https://play.google.com/store/apps/details?id=com.collectingsmiles.colors
https://play.google.com/store/apps/details?id=com.collectingsmiles.colorsnote (for Galaxy Note devices)

The app is free to download, but will have certain restrictions in place (e.g. limited save slots). These restrictions can be unlocked when you buy the full license ($4.99 USD) from within the app. I'd say it's worth a shot. I also have a copy of Colors! 3D for the 3DS for about the same price and I knew the Android version wouldn't disappoint me either.

Artflow. It supports styluses and is by far the best in terms of options.