Privacy Policy
Effective October 2, 2026 · 中文
FretFlow is a guitar practice app for iPhone and iPad and a website at www.fretflow.io, made by Haoge Wu. This policy explains what happens to your data when you use them.
Summary
- No account is needed. FretFlow has no ads or advertising tracking and does not sell your data.
- Media you choose to analyze is sent to our analysis service. Server analysis jobs have a 24-hour retention period, as explained below.
- Practice settings, saved sessions, saved scores, imported score files and your practice log are stored on your device. On iPhone and iPad, saved scores sync through your own iCloud account when iCloud is on.
Media you choose to analyze
When you start an analysis, media is sent over HTTPS to our analysis service to detect chords and notes, separate audio when requested, and play back the result. The iOS app uploads the selected file, including video if you selected a video. The website tries to extract and upload only the audio; when that is not supported it uploads the original file. Selecting start and end times limits analysis, but does not trim the upload.
Video links
If you paste a link to a public video (for example on YouTube), our server fetches only the section you select, analyzes it and deletes the audio right after the analysis. The app and the website never receive the video or audio file; playback uses the platform's own embedded player.
Server retention
Analysis jobs are retained for 24 hours from creation. Finished or cancelled jobs older than this are removed during automatic cleanup, normally checked every five minutes while the service runs. Queued or running jobs are kept until they finish or are cancelled. Cleanup removes the job's remaining uploaded media, audio tracks and results; original files may be removed earlier during processing. Sing-along tracks separated from your recording belong to the same analysis job and follow the same cleanup. Scores you save are kept on your device (and, on iPhone and iPad, in your iCloud), not on our server. Results or audio you save on your device are separate local copies.
Demo analyses
"Try chord demo" and "Try Solo demo" analyze sample audio that we provide. They do not upload anything from your device.
Session cookie
So that only you can see your own results, our server sets a random session identifier (a cookie that expires after 30 days). It is used to associate requests with your analysis jobs, and is not used for advertising or analytics. The website also saves your chosen language in a preference cookie.
Saved scores and iCloud
FretFlow has no accounts. Saved scores (detected chords and notes, your corrections and settings, the title, and source-video attribution when applicable) stay on your device. On iPhone and iPad they sync through your private iCloud database when iCloud is on; we cannot access that data. Deleting a score removes it from your devices. Deleting the app removes its local data; iCloud data can be managed in Settings → [your name] → iCloud. Exported files are managed separately. If you created an account in an earlier test version, email us and we will delete it and its scores.
On-device features
The tuner uses the microphone only while it is open; the audio is processed on your device and is never recorded or uploaded. Sing-along lyrics are recognized on your device. Your practice log stays on your device.
Service logs
Our hosting providers (Vercel and Cloudflare) process technical data such as IP addresses to deliver the service and protect it from abuse. We also retain operational records, including analysis-job status, request times and technical errors, to troubleshoot the analysis service. These records can be associated with analysis tasks and their session identifiers. Service logs are handled separately from the 24-hour analysis-job cleanup.
Website analytics
The fretflow.io home page uses Vercel Web Analytics to count page views without cookies. The iOS app does not include any analytics or crash-reporting SDK.
Data on your device
Practice settings, tone presets, saved sessions, saved scores, imported scores and your practice log are stored locally. You can remove website data using your browser's site-data settings. On iOS, deleting the app removes its local app data; files you export or share and copies kept by your device's backup service are controlled separately.
Third-party players
If a feature shows a video from YouTube or TikTok, that player is loaded from the platform itself, and the platform's own privacy policy applies to it.
Children
We do not ask for a child's name or contact details. If you believe a child has submitted personal information, contact us so we can address it.
Your choices
You can use every offline feature without uploading anything. To ask about or delete your data, email khalilwu69@gmail.com. Server copies follow the retention policy above. If you email us, we receive the contact details and information you include and use them to respond to your request.
Changes
We'll update this page and its effective date when this policy changes.
Contact
Haoge Wu · khalilwu69@gmail.com