Envision is a visualization toolkit for fast composite, interactive and animated visualizations. It's adapted to work with Flotr2.
Flotr2 & envision support Android, iOS and new Blackberries, any modern browser with Canvas, and IE7+ with FlashCanvas / excanvas. I've seen it in IE6 too, but I do not test that browser.
I have written another library, envision.js, which is more suitable for realtime data. Here's an example: http://humblesoftware.com/envision/demos/realtime. Envision here is adapted to Flotr2, but working with it is higher level than working with Flotr2 directly.
Maintainer here. It is ~30kb gzipped, and is modular but there is no modular build yet. Individual plugins and chart types are not required, which cuts out a lot of the size.
The 100kb minified unzipped is a concern of mine, however. As the library evolves, keeping it trim and trimmer is a goal.
Envision.js is a new library for fast, dynamic and interactive HTML5 visualizations. It ships with templates for a TimeSeries, a Finance chart similar to Google or Yahoo, and an API for building custom visualizations. Modern browsers, IE 6+ with FlashCanvas, Android and iOS webkit are all supported. MIT Licensed.