[Kovri](https://gitlab.com/kovri-project/kovri/) is a C++ implementation of the I2P network which was proposed to be integrated in Monero. At the moment the future of this I2P router is unclear and an integration with Monero is not planned.
Read [anonimal's FFS proposal](https://forum.getmonero.org/9/work-in-progress/86967/anonimal-s-kovri-full-time-development-funding-thread) for more details and for reasoning behind the project. Also read the FAQ and User Guide in the [Kovri repository](https://gitlab.com/kovri-project/kovri/).