FretUp

Music practice on your phone, with audio and local progress.

Identified technologies

Flutter / DartAudioOffline

The problem

Music practice on a phone needs exercises, audio playback and progress tracking, with music rules kept separate from device details.

The solution

FretUp brings music practice activities into an app with local progress and preferences. Native features support the Android and iOS experience.

What makes up the solution

Flutter/Dart app with music rules, audio ports and progress stored on the device.
View technical details →
Kotlin integration on Android for audio, timing and widgets.
View technical details →
iOS extension in Swift/WidgetKit with controlled state sharing with the app.
View technical details →

Project scope The offline activities and audio described here do not need an account or remote database. The website presents the product and links to the app stores.

Download the app

Availability and requirements are set by each store.

In pictures

App screenshots.

Archived Android screenshots in Portuguese from the September 2026 release materials: home and note identification practice. These show that app version.

Home: guidance and access to practice activities.Open original image ↗ (new tab)

Practice: fretboard note identification and an answer explanation.Open original image ↗ (new tab)

My contribution

I designed and developed FretUp, from its music architecture to the Flutter app, native Android/iOS features and website. The structure separates exercises, audio playback and device features.

Architecture overview

Music rules are separate from the UI. Audio ports control playback. Progress is stored locally.

Technical structure

Technology by module.

The product combines a Flutter app, native integrations and a static website for presentation and distribution.

What each part does and which technologies support it. A module in the code does not mean all its features are complete or published.

01 / Existing code

Mobile app

FlutterDartjust_audio

Music practice and local progress.

Music rules, application, presentation and audio ports separate exercises from playback and interface details.

02 / Existing code

Android integration

KotlinAndroid SDKAppWidgetProvider

Android-specific features.

Audio/timing integrations and widgets support the Flutter runtime. They are not a second independent app.

03 / Existing code

iOS integration

SwiftWidgetKitApp Groups

iOS-specific features.

Widget extension and controlled state sharing with the app.

04 / Existing code

Website

HTMLCSSJavaScriptPython

Public PT/EN site and download links.

Python builds static pages from templates and localized content. The browser receives HTML, CSS and JavaScript.

How the parts connect

Music rules guide app activities. Audio ports and native integrations handle the device. The website presents the product and links to stores without running music logic.