The catalog reached 42 apps one trade at a time, and the question of what to build next comes up more than almost anything else we decide. It would be easy to chase the biggest exam categories and call it strategy. We don't. A new VoltExam app only earns a place in the catalog when three things line up: real demand from people who'd use it, a body of rules stable enough to teach against, and an exam defined clearly enough that we can do it properly. Here's how that actually works.
We started in the electrical trades, and grew the catalog as customers asked for more. That phrase does a lot of work. We have never built a trade because a spreadsheet said the market was large. We build the next one when the pull is real, the source material is solid, and we're confident we can ship something we'd be proud to put our name on. When any of those is missing, the app waits — even if the category looks tempting.
The clearest signal is people asking. A licensed electrician who just added a fire-alarm ticket tells us what they wish they'd had. A plumber studying for backflow certification writes in. Search interest, app-store traffic, and the questions that land in our inbox all point the same way, and when they converge on a trade we don't yet cover, that trade moves up the list. The pattern repeats so often it became its own article — the person who already passed one exam and is back for the second ticket. Demand from people already in the trades beats a big abstract number every time, because those are the people who will actually open the app the night before a test.
We don't build the trades that are biggest. We build the ones where real people are asking and we can teach the exam honestly.
A VoltExam app is only as good as the rules underneath it. Some exams sit on a well-defined, widely adopted code — a published edition, a clear adoption cycle, jurisdictions that mostly agree. Those are a pleasure to build: every question can be tagged to the exact code section, and the explanations come from a real, citable book. Other certifications rest on guidance that shifts constantly or splinters across dozens of incompatible local rules. We can still build those, but they cost far more to keep honest, and keeping every app current is a standing commitment, not a one-time effort. So the stability of the underlying code is a real factor in what we take on, and in what order.
The last test is whether the exam itself is defined clearly enough to respect. We want to know what the licensing body actually tests — the blueprint, the format, the weighting — well enough that practicing in our app feels like practicing for the real thing, not a generic quiz wearing the trade's name. If an exam is vague, undocumented, or changes without notice, we'd rather wait than ship something that sets a learner up to study the wrong material. The whole promise of the company is in the tagline: software for the trades, built so people pass. An app we can't build to that standard doesn't ship, however much demand it has.
Running every trade through the same three questions is what keeps 42 apps feeling like one company instead of forty side projects. It's also why the catalog grows in a particular order — electrical and construction first, then transportation, health and safety, beauty, healthcare support, and the business and finance exams — rather than all at once. Each new app inherits the same code-tagged questions, the same explanations from the real book, the same progress engine, and the same fully offline study. The bar to join the catalog is high on purpose. When a trade clears it, the people in that trade get the same thing everyone else already has.
If your trade or certification isn't in the catalog yet, that's the most useful thing you can tell us — it's exactly the demand signal that moves a build up the list. The next app is almost always one a real tradesperson asked for.
This article describes how Deeun prioritizes its own product roadmap; it is not a commitment to build any specific app on any timeline. See voltexam.com for the current catalog.
Read next: From One App to 42 — how the catalog grew → · All articles · About
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