NK Tools
This is the index of all things NK-related.
BTD6
For NK's latest TD game, we have an income calculator, round information, and shareable monkey knowledge trees.
BTD5
The main page here is for listing daily challenge information, but there is also a modding tool for those who are that way inclined.
BMC
Find out contested territory maps, or calculate honour.
SAS4
The tools here allow you to calculate DPS, armour values, and prices, as well as there being a gallery of all the guns and armour.
Fortress Destroyer
Not even a tool, just writing down how I managed to get the web version running since Unity web player was deprecated.