Hi, I’m Hidekazu.
I build software the way I wish more people would: privately, transparently, and without surveillance baked in.
AI AutoSite started as a personal frustration: most modern web tools demand sign-ups, push ads, and quietly send your data to third parties — even when none of that has anything to do with the job they’re supposed to do.
So I started building the tools I wished existed. They run entirely in your browser. They don’t need an account. They don’t track you. There are 77 of them now, with new ones added regularly, and the code is open source on GitHub under the MIT license.
Alongside the web tools, I ship native iOS apps under the same philosophy. Tuck Voice transcribes your voice memos on-device with Whisper, no cloud involved. DealKit is a CRM for creators with no analytics SDK in sight. TimeSee is a visual timer designed for ADHD brains, with a real Apple Watch experience.
The umbrella for all of this is Signal — a one-person studio I run from Fukuoka. The name is a reference to clarity and transparency, the same values that shape how I build.
What Signal stands for
Four principles, applied to every tool and app I ship.
Privacy First
I collect minimal data and never track or sell your information. Your content stays in your browser.
Instant & Simple
Tools that work immediately — no registration, no complex setup, no learning curve.
User-Centered
Every feature is built based on real needs, not engagement metrics or monetization goals.
Open & Transparent
Most of the code is open source on GitHub under MIT. Transparency over black boxes.
How I build
I’m one person, but I ship at the pace of a small team. That’s possible because I work async, write everything down, and use modern AI-assisted tooling the way professional software studios do in 2026.
What that means in practice:
- →I take full responsibility for every line that ships. AI is a tool, not a collaborator that gets its name on the commit.
- →User data — yours, mine, anyone’s — never enters a third-party AI training pipeline. The privacy promise is non-negotiable.
- →Decisions are documented as Architecture Decision Records, so the code doesn’t need me to explain it.
- →Deadlines are commitments, not estimates. If something is at risk, I say so 48 hours in advance, with a written plan — not a last-minute apology.
Honesty about how the work gets made is part of being privacy-first.
Other things I’ve made
Native apps that follow the same playbook.
Want to work with me?
Signal also takes on a small number of client projects each year — privacy-first iOS and Next.js work, on monthly retainers.