Activity Sparks
by pantsonhead on WordPress.org

Example implementation (3 instances)
Activity Sparks is a highly customizable widget to display a “sparkline” style graph in your sidebar indicate post and/or comment activity. This plugin leverages Google’s Chart API, so does not require the PHP GDI library. Customization options include Title, size, colour, background transparency, caching period, activity granularity and period.
Active installations10+
Weekly downloads
7-12.50%
Version0.6.1
Last updated8/18/2015
WordPress version2.8
Tested up to4.2.38
Tags
activitygraphsidebarwidget