I built an iOS chiller calculator for HVAC/R professionals

Samet Nail | AI App Builder — Thu, 17 Sep 2026 17:39:32 +0000

I work in refrigeration/HVAC, so I decided to build a tool around a problem I already understand instead of chasing another generic app idea.

The result is Chiller Calc Pro, an iOS app for common chiller and chilled-water calculations.

It includes things like cooling capacity and water flow, chiller sizing, glycol correction, pump calculations, pipe sizing and velocity, pressure drop, buffer tank sizing, and energy/COP calculations.

The interesting part for me was building for a very narrow professional audience.

Consumer apps can have a much larger market, but with a niche tool the user intent is much clearer. If someone needs a chiller calculation, they usually have a real job to do.

I’d be curious to hear from other developers:

Have you had better results building for a niche you know well, or for a larger general audience?

App Store: https://apps.apple.com/us/app/chiller-calc-pro/id6799268602

I built WebArena to make website discovery competitive

Samet Nail | AI App Builder — Wed, 16 Sep 2026 18:17:05 +0000

I’m a solo builder, and one problem I keep running into is that launching a website is often easier than getting anyone to discover it.

That led me to build WebArena.

Instead of another static directory, WebArena turns discovery into a live competition.

Website owners can submit their projects and use credits to compete for visibility, while users can browse the leaderboard and discover new websites, products and indie projects.

The interesting part has been figuring out the balance between competition and actual discovery.

I don’t want the experience to become simply “whoever spends the most wins.” The leaderboard still needs to be useful and interesting for people who are there to discover things.

WebArena is currently live on iOS.

Tech stack:

React Native / Expo
Firebase
RevenueCat

I’d especially like feedback from other builders:

Would you submit your own website to something like this?

And what would make you come back regularly to browse the leaderboard?

App Store: https://apps.apple.com/us/app/web-arena/id6804822497

DEV Community: Samet Nail | AI App Builder

I built an iOS chiller calculator for HVAC/R professionals

I built WebArena to make website discovery competitive