Never fear: our price graphs aren't gone, they've just moved! They've been slightly relocated to give you information that's more tailored to your particular search.
On the website:
After you enter your flight search, you will see a price graph in the upper right-hand corner of the search results screen, which shows how the price has fluctuated recently and predicts how it may fluctuate in the near future:
You can also hover over a particular flight to see if there is a price history for that specific flight on that airline:
On iOS devices:
The price graph will appear at the bottom of the screen when you select your travel dates. Additionally, you can see the price history of a specific flight by selecting that flight: