This document discusses and compares several free online formative assessment tools: Kahoot, Padlet, Socrative, Quizizz, and Wizer.me. It provides an overview of each tool's features, including likes such as ability to embed media, provide reports, and engage students. It also notes potential limitations such as reliance on internet connectivity, interface simplicity, and difficulty tracking anonymous student responses. The document aims to help teachers choose appropriate formative assessment tools to measure student understanding using technology.