There's lots of useful sites that can you use to get your Travian experience better. I will shortlisted them to the my favorite tools.
This is the best cropper map for travian that I've ever used. With this site, you don't need to use Travian cropper finder that Travian Gold Club feature offered because you can get it for free here.
In this site, you can make your own combat simulator that are better from what travian have offered. Their offense calculator will direct you to know what are the best combination of troops that can be used to get the highest attack value and time needed to construct them.
another services offered by them.
Conquering calculator - you can use this tool to calculate how many time you need to attack to conquer the village.
Unit attribute calculator - this tool is can be use to determine what is the best troops to be developed using based on the crop consumption, time needed, and their cost.
Hero Calculation - You can calculate the strength of your hero and time needed to generate them.
Travian toolbox is a great site that offers lots of tools to help you play better in travian. Their troops comparison are very useful to help you to choose what is the best troops to use. Not forgetting their Travian Time Calculator is one of the important tools for you to calculate the ETA in your mission.
Tools that can be use to generate travian report
To get the server statistic or analyze travian player in your server, this site is good for you
Especially For Travian T4 Version *under construction
For all the information needed about Travian T4,
Travian T4 Developer Blog : http://dev.travian.org/
Useful Sites That works with Travian T4
Script that works with travian T4
Travian resource bar plus
i will update if i find any site or tools that are related to be use in travian.