Hootsuite has supported an Instagram app for it's software since mid-2012 I think.
To get Instagram on your Hootsuite dashboard, you'll need to download the app from the Hootsuite app directory, and then create a new tab (or add it to a pre-existing one) to start using and managing Instagram via Hootsuite.
I'd also recommend checking out the #HootTip blog post that explains this in more detail, and there's also a nifty little explainer video here:
