Promptloop is an AI tool that integrates with Google Sheets and Excel to transform, extract, and summarize text using pre-built AI models. It allows for custom model training and can be used for tasks like analyzing sales lists, unpacking survey responses, drafting email outreach, and unlocking the potential of unique and valuable data. The tool can be used for free and offers one-click engines for custom solutions, with a focus on simplifying spreadsheet formulas and workflow.