What are some alternatives?
When comparing LibreTorrent and Koinonein BitTorrent Client, you can also consider the following products
qBittorrent - Lightweight and open source torrent client that runs on all major platforms.
dottorrent-gui - An advanced GUI torrent file creator with batch functionality, powered by PyQt and dottorrent.
Transmission - Transmission has the features you expect in a BitTorrent client: encryption, a web-based interface...
PicoTorrent - PicoTorrent is designed to be a tiny, easy-to-use BitTorrent client with low memory usage.
Bitford - BitTorrent client for Chrome that can stream videos while they're being downloaded
Tixati - Tixati is a peer-to-peer file sharing program that uses the popular BitTorrent protocol.