In the generative AI app market, AI companion apps that let users interact emotionally with specific characters are growing the fastest, while Korean apps are standing out in global revenue growth rankings.

A report released by mobile data analytics firm Sensor Tower on Tuesday said worldwide in-app purchase revenue for AI companion apps rose about 30 percent in the first quarter of 2026 from the previous quarter. That was the highest growth rate among generative AI subcategories such as AI assistants and AI content creation.

By quarter-on-quarter revenue growth, Zeta, an AI character chat app launched in April 2024 by Scatter Lab, known for the AI chatbot Lee Luda, ranked first overall. Zeta, which lets users create characters and continue stories, also ranked first year on year, boosting its presence as the only Korean app in the top 10. Uif ranked sixth and Melting eighth, giving Korean apps 3 of the top 10.

In terms of absolute revenue, U.S. apps PolyBuzz and Chai kept top spots, while Zeta ranked third globally and Lovey Dovey seventh.

Zeta’s growth was driven by its push into Japan. As of March 2026, monthly downloads were about 400,000, the highest level in about 28 months since launch. In 2026, Japan overtook South Korea as its biggest download market, and in March the order shifted to Japan, the United States and South Korea.

Zeta is deploying market-specific marketing strategies, including ranking first among generative AI apps in the share of TikTok ad exposure in the first quarter. In the United States, organic inflows also rose after it expanded advertising focused on mobile app channels.

A multi-platform strategy is also supporting growth. Zeta’s web traffic has kept rising after monthly visitors topped 1,000,000 at the end of 2025. In the first quarter, app-only users rose 81 percent from a year earlier, web-only users increased 87 percent, and users who used both app and web climbed 157 percent, the fastest growth.

Sensor Tower said, "Even within a revenue structure centered on the United States, Korean apps are showing notable growth in the AI companion market, and whether they expand globally will be a variable that shapes the market landscape."