A robonoid is a small piece of machinery made by Peridot. The goo inside is a equal mix of souls, shade blood, and toothpaste. The stuff inside is able to repair anything and the robonoid uses tech similar to Prometheans to operate its legs. Also not much is known about what they are made of, only that it has properties similar to plastic, but breakable like glass. They are essential for typing in the chat on the Steven Universe Wiki while rainbow Suga-Perilite is AFK. Also for fixing the computer every time rainbow Suga-Perilite smashes it accidentally.
"Be thankful for them, they make life easy" - Peridot
By the art of fixing things they are able to repair the damages caused by the sugilite part of rainbow Suga-Perilite.