About Simple Memo
An app built by an engineer who loved Captio, created to bring back that experience after the service shut down. No compromise on speed. No compromise on privacy.
Developer Story
I started using Captio around 2013. At a time when most memo apps were competing on "organization" and "management" features, Captio made the opposite argument: launch, type, send, done.
I was completely hooked. It wasn't a meeting notes app, a task manager, or a cloud-synced notebook. It was a tool for firing the thought in your head directly to your email, with zero friction. That frictionlessness was the whole point — no context-switching, no deciding which folder it goes in, no barrier between the idea and the capture.
"What would I do if Captio ever disappeared?" — I asked myself that more than once over the years.
In October 2024, that fear became real. One day, Captio was simply gone from the App Store. No official announcement, no migration path, no farewell post. Just silence. Some speculated it was related to Gmail API dependency changes, but no one knows for certain.
That evening, I decided to build it myself. Out of respect for what Captio had been, and out of a stubborn belief that this kind of tool deserves to exist, I opened Xcode and started writing UIKit code from scratch.
Mission
Taking a memo shouldn't require this much friction. Launch, write, send. That's all it takes for your thinking to move forward. Simple Memo's mission is to protect that pure experience — to prioritize the quality of what it already does over adding more features that dilute the core.
Development Philosophy
Technical Expertise
Simple Memo is designed, implemented, and operated by AI Ataka, a developer with over 10 years of software engineering experience. iOS app (UIKit), backend (Cloudflare Workers), and infrastructure (DNS, CDN, email delivery) — all handled by one person. The insights gained along the way are published as a dev log.
- iOS Framework
- UIKit (see why UIKit over SwiftUI)
- Backend
- Cloudflare Workers (TypeScript)
- Email Delivery
- Resend API (DKIM signed, SPF/DMARC configured)
- Security
- AES-GCM (on-device encryption), HTTPS (TLS 1.3)
- Offline
- Outbox architecture (CoreData + encryption + auto-resend)
- Minimum iOS
- iOS 16.0+
Dev Log Articles
Company Information
- Company
- Yurica Inc. (株式会社ユリカ)
- Developer
- AI Ataka
- Legal Details
- See Tokushoho (Commercial Transaction Act)
- Contact
- [email protected]