I made a cryptocurrency charting site that uses data from Poloniex: cryptohistory.org
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The focus is on making image charts that can be easily embedded anywhere.
Here is the 24 hour chart for Steem/BTC:

You might notice that this chart is very old, with just a couple hours of data on it -- Steem currently caches images and rehosts them securely, but it ignores all cache-control headers and does not re-fetch expired images. That will have to be fixed before these are usable on Steem.