Omnimeter
crossroads:omnimeter
The <item>Omnimeter/$ is an extremely important and useful tool. Right clicking with it on almost any Crossroads machine or block will provide a readout of important information, such as <thing><link:intro/heat>temperature/$, <thing><link:intro/rotary>speed, I value, energy/$, <thing><link:intro/fluid>fluid contents/$, and more.
It is expected that the player has an <item>omnimeter/$ for Crossroads machines. WAILA is not a good substitute.

Another basic tool that Crossroads uses a lot is the <item><link:essentials/wrench>wrench/$- though basically any mods' wrench will work.