impulseSV, also known simply as Impulse, is a YouTuber and Hermitcraft member. He joined in Season 3. He has close to 240,000 subscribers on his YouTube channel. He is well-known for his farm designing skills and the tutorials he creates for his designs.
iTrade is the name of Impulse's shop in the Shopping District. It is a villager-based enchanted book store. The main level features a series of chests, each filled with a specific type of enchanted book. The bottom level is a trading room, where players can purchase trading goods such as crops and paper to trade with the villagers for emeralds. Originally, Impulse charged a one-time fee of a season's pass for all services in the building. However, he eventually changed it so anyone could purchase books, but only pass-holders can trade in the bottom level facility.
Outside of Hermitcraft
Impulse has a secondary channel called impulseSV2. He posts his stream archives here.