ThemeGPT is a privacy-first Chrome extension that transforms ChatGPT's appearance with handcrafted themes — from Dracula to Aurora Borealis with animated effects. One click to apply, zero data leaves your browser. 7 free themes included, no sign-up needed. 8 premium themes with animated aurora blobs, neon grids, and twinkling starfields. 30-day free trial, $6.99/mo after. First 60 yearly subscribers get lifetime access.