VStok is an AI visibility platform for brands and mobile apps. It runs buyer prompts across ChatGPT, Gemini, Perplexity and other answer engines, then scores mention rate, share of voice, position, sentiment and trends. Site, App Store and Google Play audits plus a ranked action list. Free checker at https://vstok.net/tools/ai-visib.... Plans: Free, Starter $29, Growth $79, Agency $249.