Your tool doesn't currently show the last security update, according to your website last update was 2 months ago. Django wise, there is the Google group which you can be follow for all updates , you can also subscribe to the RSS feed of django's weblog.

Your tool seems interesting, i like the idea of being able to keep a list of all the software i use in a single place and get notified when a new update comes out(had a similar idea myself), however i would need some kind of reassurance that such an application is reliable and wont let me in the dark for some important update.