It has 3200 characters, levels 1-4 of the HSK proficiency tests. The organization is dramatically simple: look up by either the left or right elements, or the top or bottom elements, or the few that aren't slit horizontally or vertically.
I like it because it permits multiple ways of learning. I can scan all the characters with a particular radical in the left half, or right half... see patterns. Definitions are only a word or two and don't get in the way -- for full meaning it should be buttressed by a more traditional dictionary. I can look for characters at the HSK1 level and focus on those, or just avoid the HSK3 or 4. I can quiz myself on the shapes. I can look for elements which are unique, whether the core elements (pp38-40) or the outliers (those with multiple radicals in a single row). The page design is simple, but smart, and allows great flexibility in learning styles.
This is a very good resource for a set of wide, shallow views into the common character set. It doesn't deal at all with compounds, but instead helps in getting familiar with the parts which make up a compound. I'm enjoying it greatly, and I appreciate the work and thought that went into making something so exhaustive, yet so simple.