Some others that are more geared to Sprite only:
Spartan:
http://www.vitruality.com/2014/10/spartan-v1-1/
Not too bad. Has some nice generators for brick and water.
Piskel:
http://www.piskelapp.com/
Need an account for all the features (FREE). Works on Chromebooks and tablet devices. Nice way to share and learn from others.
For Smooth edge SVG there are a couple of online edtiors :
SVG edit from google : http://svg-edit.googlecode.com/svn-hist ... ditor.html
Method draw : http://editor.method.ac/
EDIT:
Piskel has a nice new standalone version that works either locally, or along with your free gallery. Linux,Mac,Win It uses node webkit <img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":)" title="Smile">