Brandon Johnson

A physics sandbox where fire, water, gas and heat interact, with guided challenges.

See inside a cooling system: TXV, refrigerant flow and a live thermal view.

A virtual workbench for placing, connecting and testing refrigeration systems.

A real-time fluid and air simulator you can stir with a finger or mouse.

An offline-ready pocket reference: PT charts, superheat/subcool and diagnostics.

Practice service calls end to end: walk-up, triage, wiring, fix and debrief.

A tablet hub of reading, number, science and art games, from letters to pixel art.

A series of books written as B.J. Calder.

A new book, currently being written.