Yggdrasil is described as 'A proof-of-concept scalable IPv6 meshnet, featuring end-to-end encryption, a unique spanning tree routing algorithm and aiming to implement novel backpressure routing metrics' and is an app in the network & admin category. There are more than 100 alternatives to Yggdrasil for a variety of platforms, including Windows, Mac, Android, Linux and iPhone apps. The best Yggdrasil alternative is Tor Browser, which is both free and Open Source. Other great apps like Yggdrasil are Tor, I2P, Orbot and Hyphanet.