Twenty years in the field. Fifteen apps for the people still in it.

I spent two decades on fuel systems and controls before I wrote a line of any of this. Every app works with no signal, because the sites that need them do not have any.

Built for the field

Written by a technician

Twenty years on fuel systems and controls. The calculations are the ones I needed myself.

Works anywhere

Fully offline

No signal in a forecourt, a riser room or a battery yard. Nothing here needs a connection.

Nothing hidden

Free reference, no signup

Nine hundred error codes and field procedures, published openly. No account, no email required.

Field toolkits

One app per trade, each built around the work rather than around a category.

🛢️ DropTubeBuilder

Fuel systems. Drop tube cuts, overfill valve placement, tank charts, EPD inspections and dispenser error codes.

Details App Store

☀️ FieldWatt

Utility scale solar. String sizing, NEC calculators with citations, inverter faults, commissioning and tracker procedures.

Details App Store

🔋 StoreWatt

Battery energy storage. State of charge, capacity fade, round trip efficiency, BMS and PCS faults, NFPA 855 and UL 9540.

Details App Store

🔥 LoopWatt

Fire alarm. NFPA 72 inspections, ground fault chasing, notification appliance circuits, voltage drop and candela.

Details App Store

🖥️ RackWatt

Data centre operations. UPS and cooling, method of procedure checklists, runtime and capacity, critical facility work.

Details App Store

🔌 PlugWatt

EV charging. OCPP faults, NEC 625 calculations, connector types, commissioning and voltage drop for charger installs.

Details App Store

Nine hundred error codes and field procedures, free

Published openly on this site. No signup, no email, and you do not need the app to read any of it.

Fuel systems

Veeder Root TLS 300, 350, 450 and TLS4. Gilbarco 500 and 700 series and Encore 300. Wayne Ovation. Franklin INCON. FE Petro.

Open reference

Solar

Inverter fault codes, combiner maintenance, tracker procedures, plan sets and drawings, Modbus and SCADA, ANSI device numbers.

Open reference

Battery storage

BMS and PCS fault families, energy management dispatch, thermal management, communications protocols, standards summaries.

Open reference

Fire alarm

NFPA 72 troubleshooting, panel trouble conditions, ground fault procedures, notification appliance circuits.

Open reference

Data centre

UPS and cooling references, critical facility procedures, method of procedure content, capacity and runtime notes.

Open reference

Why it is free

Because the answer should be findable at two in the morning by someone who has never heard of me. The apps do the calculations. The reference is just there.

Also shipped

Fifteen apps in total, including work outside the trades.

⚖️ TrialMate

Trial preparation for attorneys. Cross examination, openings and closings, trial checklist and case notes.

App Store

🧾 PaidUp Invoices

Invoicing and payment chasing for people who would rather be doing the work.

App Store

💰 Side Work Tax

Income, expenses and mileage tracking for anyone earning on the side.

App Store

See all fifteen apps →

Need something built for your crew?

Most of these apps started because a technician needed something that did not exist. If your team has a job that no software fits, that is the work I take on. Fixed price, working software in weeks, built by someone who has stood on the site.

Tell me what your crew needs