FieldDojo

FieldDojo is a multi-trade field calculator for construction, HVAC, electrical, and plumbing professionals. Instead of juggling a handful of single-purpose apps and a code book, a tradesperson gets 57 calculators in one place — each one showing the formula it used and the code section it's based on.

We built it offline-first because job sites rarely have reliable signal, and we made every result something you can hand to an inspector: the wire-ampacity number sits next to its NEC table reference, the duct-sizing result next to its ASHRAE basis. Results adapt to six regional code sets — US, Canada, UK, EU, Australia, and New Zealand — and a built-in offline reference library covers the code sections behind them.

One note if you check the Play Store link: the package id reads com.notchip.calcrig. The app shipped under our earlier working name, CalcRig, and Android package ids are immutable once published — same app, same developer account, renamed before launch marketing.

Trade calculation tools are fragmented — one app for wire sizing, another for duct sizing, and a code book to verify either. Switching between them mid-task is slow and error-prone.

The free alternatives are shallow: they spit out a number with no formula and no code reference, so the result is impossible to defend to an inspector or a client.

And almost none of them work where the work happens. Job sites have patchy connectivity, so anything that depends on a live network is unusable exactly when it's needed.