Bulgaria: www.bdzmap.com  Live tracker with locomotive and unit allocations

Hungary: https://kozlekedesiklub.hu/vonatinfo/en.html Live tracker with locomotive and unit allocations

Portugal: https://trainstatus.pt/ Live tracker with locomotive and unit allocations based on user input

Sweden: https://www.sj.se/en/search-journey Live tracker by train number, locomotive allocation not viewable

EGTRE

Enthusiasts Wiki for European rail travel

ERG

Fantastic gen resource for all, the original and the best.

FIP Guide 

A very useful website for those who are holders of FIP privileges, they also have a Discord server