<portfolio/>
Portfolio
Projects built by JJ Software, applied to real businesses.
Our own app for iPhone and iPad
Hotaru
A flashcard app built and published by JJ Software. It turns notes, photos and PDFs into cards with Apple Intelligence, on device, and schedules reviews with FSRS, the spaced repetition algorithm behind Anki.
- —Native SwiftUI and SwiftData, with Liquid Glass, widgets, Control Center and Siri
- —On-device Apple Intelligence, with cloud AI through OpenRouter as a fallback
- —Sync and shared decks on Cloudflare Workers and PlanetScale Postgres
- —Hotaru Pro subscription through the App Store with StoreKit 2
- —In English, Portuguese and Spanish, with 250+ ready-made decks
Our own app for iPhone, iPad and Apple Watch
Everyish
A habit tracker designed with ADHD brains in mind, built and published by JJ Software. Instead of resetting your streak at the first slip, it uses grace days, guided routines and a dopamine menu to help you come back.
- —Native SwiftUI and SwiftData, synced through the user's own iCloud
- —Widgets, Live Activities, Siri and an Apple Watch app
- —No account and no server: data never leaves the user's devices
- —Everyish Plus subscription through the App Store with StoreKit
- —Available in English, Portuguese and Spanish
Our own app for iPhone and iPad
Cobrei
An app for Brazilian micro-entrepreneurs (MEI) and freelancers, built and published by JJ Software. It tracks hours per client, turns them into PDF invoices and receipts with a Pix QR code, writes a ready-to-send payment reminder for WhatsApp, and keeps the MEI revenue limit and monthly tax in view.
- —Native SwiftUI and SwiftData, synced through the user's own iCloud
- —Timer with a Live Activity, Dynamic Island, widgets, Control Center and Siri
- —Pix QR codes built on the Central Bank's BR Code standard, generated on device
- —No account and no server; Cobrei Pro subscription through the App Store with StoreKit
- —Real-time subscription alerts from a custom Cloudflare Worker
Custom micro-SaaS platform
Equivolt
SaaS platform for lightning protection (SPDA) risk analysis under the Brazilian standard ABNT NBR 5419-2:2026. Engineers enter the structure data and get the full technical report — risk analysis, calculation memo and system description — ready to deliver.
- —R1, R3 and damage frequency calculated per NBR 5419-2:2026
- —Lightning density (NG) resolved per municipality from the standard's Annex F
- —Scenario simulator and full revision history for every report
- —Export to PDF, Word and Excel, branded with the firm's letterhead
- —Recurring subscriptions across individual, team and company plans
Custom corporate website
RSJV Engenharia
Corporate website for an electrical engineering company, specialized in technical inspection reports. Built from scratch with Next.js, focused on local SEO for the São Paulo region.
- —Built with Next.js, no WordPress
- —Local SEO structure with per-service and per-city pages
- —Structured data (Schema.org) for local business
- —Contact form with email delivery and WhatsApp button
Got a project in mind?
Tell us what you need to build and we'll get back to you with a straightforward proposal.