Decentralized microblogging using Sone, the twitter-like system on Freenet. Freemail, the encrypted email system. FMS, the forums. I also use the distributed data store for storing data. Basically anything you'd use IPFS for but more anonymity.

Here's an example of using it for the backing store for my blog: https://bluishcoder.co.nz/2015/09/14/using-freenet-for-stati...

Here's a series of articles on writing dynamic apps for Freenet - in this case chat-like things http://www.draketo.de/light/english/freenet/communication-pr...

In addition to what doublec described: I use Freenet for confidential communication with friends. Encrypted Freenet traffic provides a cover which not only masks when we talk and what we talk about but also whether we talk at all.

For details and how to do it, see http://www.draketo.de/english/freenet/connect-speak-freely