I just put the finishing touches on Chartlets, a library for making tiny charts for mobile and tablet web apps:
While most data visualization libraries are biased toward big displays, Chartlets assumes the opposite. Not only are Chartlets small, the library itself weighs in at under 3K. And the API is drop-dead simple, requiring no programming knowledge to render a basic chart. Chartlets can be defined entirely in HTML:
<canvas class="chartlet" width="65" height="65" data-type="pie" data-sets="[1 2 3 4 5]" data-opts="theme:money"></canvas>
Check out the full docs and examples at chartlets.com.