If you want a tool that lets you chat with AI without breaking out of whatever app or workflow you're in, AI Anywhere is worth a look. It spans many apps including browsers, PDF viewers, email clients, messaging apps, Office apps and code editors so you can read, write and code without having to copy and paste. It also has a Chat function for discussing any subject and a Personalized Copilot that lets you customize shortcuts and prompts. The Pro version adds AI chatbot abilities and GPT-4 access, so it's a good general-purpose tool to improve your productivity.
Another alternative is QuickyAI. This tool converts any webpage into a ChatGPT interface, so you can chat with any webpage without leaving the page you're already on. It supports GPT-4 and GPT-4 32k models, and offers features like custom prompts and one-click content summarization. That can be very useful for boosting productivity by making ChatGPT more useful and convenient for tasks like answering emails and rewriting paragraphs.