Apps similar to Mignon UI include Local Waifu. It's paid, but SillyTavern and Janitor are free. In total there are three AI Chatbots like Mignon UI for Windows, Android, iPhone, Linux and the web.
AI companion for macOS operating fully offline with customizable characters, long-term memory through knowledge graphs and embeddings, no cloud storage, no telemetry, privacy-focused, RAM-based model recommendations, and a one-time purchase with no subscription required.
Poland
EU
SillyTavern is a user interface you can install on your computer (and Android phones) that allows you to interact with text generation AIs and chat/roleplay with characters you or the community create.
Janitor is where you step inside stories instead of just reading them. It's like if your favorite book let you talk to the characters and shape what happens next.
United States
