The IT-O and its successor IT-000 were designed with one twisted purpose in mind: to torture subjects to the breaking point. They used drugs, needles, electricity, and more to get the truth.
Slayn & Korpil repurposed parts of the B-Wing starfighter and some shuttles to create a transport for the Resistance. It carried soldiers (along with senators and royalty) to the front lines in the fight against the First Order.
The First Order used the D-93 Incinerator flamethrower to destroy villages (and evidence). It was partially practical, but also a demonstration of absolute power.
The First Order’s bases and starships were guarded by wandering sentry and patrol droids. They kept their “eyes” out for any suspicious activity.
The thick-skulled steelpecker was another one of Jakku’s creatures you went out of your way to avoid. It was fiercely dedicated to destroying anything shiny.