Sotto is a local AI chat app that runs entirely on your iPhone. No cloud. No servers. Everything happens on your own device, and your conversation data never leaves it. ■ Fully on-device AI The AI models in Sotto run directly on your iPhone's chip. No internet connection is required. Whether you are on a plane, in the subway, or anywhere without signal, you can start a conversation with AI anytime. From answering questions and brainstorming ideas to helping you write, Sotto is designed to be a reliable everyday companion. ■ Your conversations stay private Every conversation in Sotto is stored only on your device. Nothing is sent to a server. What you ask, what you write, and what you talk about stays with you. Sotto is built for people who want privacy to come first. ■ Extra protection with passcode lock Set a 4-digit passcode and the app will lock every time it is opened. This helps prevent anyone else from seeing what's inside. When passcode lock is enabled, the app screen is also blurred in the app switcher to help protect your privacy from accidental glances. ■ Choose the model that fits you Sotto lets you choose from multiple AI models depending on how you want to use it and which device you have. The "Plus" model is recommended when you want more capable answers, while the "Lite" model is better for a faster, lighter experience. Models can be downloaded in the app and switched at any time. ■ Regular model updates and additions The AI models available in Sotto are updated regularly. We will continue improving model quality and adding new models over time so you can enjoy better responses and a better AI experience with each update. ■ Start for free You can try Sotto with a local AI model for free. After that, you can make a one-time purchase of Sotto Pro to use it without message limits. Because Sotto Pro is a one-time purchase, there is no monthly subscription fee and you can keep using it permanently. -- Important Notes -- Because Sotto runs AI models directly on your device, response generation may take time depending on your iPhone's performance, and some features may not work properly on older devices. For the best experience, we recommend iPhone 15 Pro or later. An AI model download is required before first use, and we recommend downloading over Wi-Fi.