Amateur Directories
QRZ – This is the go-to online directory of Radio Amateurs in the World – https://www.qrz.com/
Propagation and DX Tools
PSKreporter – Shows your propagation on FT8 around the world – https://pskreporter.info/pskmap.html
DXcluster – A traditional way to find DX stations calling – https://www.dxheat.com/dxc/
Online Logs
ARRL Logbook of the World (LoTW) – https://lotw.arrl.org/lotwuser/default