Open AI makes it quite easy to find the best AI services among the so-called custom GPTs. “Generative Pretrained Transformers” (GPTs) are text-based dialogue systems based on artificial intelligence. ChatGPT users can train their own models and make them available on the platform. Three million models are said to have been generated in this way. The custom GPTs complement ChatGPT's general language model. Open AI sorts them at chatgpt.com/gptps by popularity and also by categories such as writing, productivity, research, education, lifestyle and programming. Furthermore, when you call up such a specialist, you can find out their ratings from users and how many chats have already been conducted with the service.