Free interactive tools for every CS classroom

I've been building a set of browser-based tools for GCSE and A-Level CS students and wanted to share them here in case they're useful to others.

Five tools, all free, no login required:

Boolean Algebra Practice - Worked examples covering every law on the spec. Students step through the solution one line at a time rather than just reading the answer.

SQL Sandbox - A SQLite engine running entirely in the browser. Students write and execute real queries against six preloaded databases. Nothing to install or configure.

Trace Table Generator - Step through sorting algorithms, searching, and pseudocode questions line by line. Designed around the style of questions that come up in exams.

LMC Simulator - Visual Little Man Computer with mailboxes, an accumulator, and step-through execution. Useful for making the fetch-decode-execute cycle concrete.

Logic Gate Builder - Place gates, draw connections, and watch signal propagation in real time. Generates a truth table automatically from the circuit.

All tools are live at: https://www.codebash.co.uk/tools

Happy to take any feedback from the community and hear whether they're hitting the mark.