About the Developer
honeymarron
I build and run two iPhone apps solo: Award Certificate Creator and VoicyCare. Hi, I'm honeymarron.
Profile
- Handle: honeymarron
- Based in: Japan
- What I do: Full-stack software engineer / iOS app developer
What I've worked on
I've been doing this for a while, and I've built systems across quite a few industries:
- Large-scale enterprise and public infrastructure web systems
- Business systems for the financial industry
- Public transit services
- Mobility platforms
- Backend systems for the education sector
- Large-scale entertainment apps (hundreds of thousands of DAU)
- VR / metaverse platforms
- IoT × voice AI services
I've worn many hats — server-side engineer, SRE, project manager, scrum master — depending on the phase of the project. Backend, frontend, infrastructure: I can work hands-on across the whole stack.
Tech stack
What I usually reach for:
- Languages
- Ruby on Rails / Node.js / Go / TypeScript / Python / Scala
- Infrastructure
- AWS (ECS / RDS / Lambda / StepFunctions / Glue / CloudFront), Azure, Terraform, AWS CDK
- Mobile
- React Native / Expo / Flutter / Swift
- Data
- PostgreSQL / MySQL / DynamoDB / Elasticsearch / PySpark
Lately I've been using AI-assisted coding tools (Claude Code, Cursor) to speed up development, and building voice-related products with Azure Speech and OpenAI.
Apps I build solo
Award Certificate Creator
An iOS app for creating award certificates. Available in 175 countries with around 1,000 monthly active users. Pick a template, type the text, and you have a print-ready certificate. I do everything myself — design, development, distribution, operations, and marketing.
- Availability: 175 countries
- Monthly active users: approx. 1,000
- App Store rating: ★4.3 (as of May 2026)
- Languages: Japanese & English
Award Certificate Creator Official Site → / App Store →
VoicyCare
A free music player app that amplifies earphone and headphone volume up to 500% (5x). Available in 175 countries. Features a 5-band equalizer, volume presets, AB repeat, bookmarks, playback speed control (0.5x–2.0x), and multi-cloud playback via the iOS Files app (iCloud / Dropbox / Google Drive / OneDrive). Designed with large text and buttons, ideal for users with hearing difficulties and older adults.
- Availability: 175 countries
- App Store rating: ★5.0 (as of May 2026)
- Languages: Japanese & English
- Volume amplification: up to 500% (5x) via custom DSP implementation
Certifications
- Applied Information Technology Engineer (Japan)
- Software Development Engineer (Japan)
- Fundamental Information Technology Engineer (Japan)
About this site's articles
The articles on this site are written to help users of Award Certificate Creator and VoicyCare, based on research I conducted while building and operating these apps.
If you spot anything incorrect, please reach out via the contact form.
What I value
One phrase I really love is "Cherish love and consideration." I try to carry that same spirit into everything I build.
An award certificate is a way to say "thank you" or "well done" to someone. I want this app to be a small bridge that turns those everyday feelings — gratitude, affection, encouragement — into something a little special.
- A nudge to say "thank you" — Words we feel shy to say out loud often land easier on a certificate. I'd like the app to be that kind of nudge.
- Don't leave anyone behind — Across ages, languages, and devices, I want it to be easy to pick up and use.
- Quietly useful, for the long run — Not flashy, but always there when you need it.
Public knowledge
- 個人開発者の SEO は Bing Webmaster Tools から始める (note, Japanese) — A Japanese article on why 90% of search traffic to a solo dev site can come from Bing, with practical Bing Webmaster Tools usage including URL Submission, Block URLs, and API automation.
- indie-dev-seo-playbook (GitHub) — Source repository for the note articles plus planned tooling. Licensed under CC BY 4.0.