I2P, the Invisible Internet Project, is meant to provide a free anonymity layer, so users can communicate anonymously using a range of applications.

Protect your communications from dragnet surveillance and monitoring by third parties.

I2P is an anonymous network, exposing a simple layer that applications can use to anonymously and securely send messages to each other. The network itself is strictly message-based (a la IP), but a library is available to allow reliable streaming communication on top of it (a la TCP). All communication is end-to-end encrypted (in total, there are four layers of encryption used when sending a message), and even the endpoints ("destinations") are cryptographic identifiers (essentially a pair of public keys).

I2P Provides You With The Following Options:

● Email: Integrated webmail interface, a plugin for serverless email.
● Web browsing: Anonymous websites, gateways to and from the public Internet.
● Blogging and forums: Blogging and Syndie plugins.
● Website hosting: Integrated anonymous web server.
● Real-time chat: Instant messaging and IRC clients.
● File sharing: ED2K and Gnutella clients, integrated BitTorrent client.
● Decentralized file storage: Tahoe-LAFS distributed filesystem plugin.

Similar:
● Why You Shouldn't (Mostly) Use Free VPN Services
● How to Enable the Windows Defender Sandbox in Windows 10 & 11