Privacy Policy, El Eje (Mac app)

Last updated: 22 June 2026

El Eje keeps a cloud backup of your edits so you can restore them, and uses them to keep the shared tango database accurate for everyone. You agree to this when you first open the app, and it is required to use El Eje. No audio is ever uploaded.

What's backed up

The app stores a snapshot of the changes you make (tied to your copy, so you can restore it):

• Your edits to title, orchestra, singer, year, genre, and lyrics, translations and credits;
• Song timings you set (per line, and where a track starts/ends);
• Measured BPM and key, your cue points, and mood/energy ratings;
• Your playlists and tandas (including which recordings you group, and in what order);
• Your difficult-word ratings;
• Acoustic fingerprints of tracks the app couldn't recognize, so they can be identified and added for everyone.

The backup is keyed to your copy of El Eje and restorable by you. It is used to improve the shared catalog, is never sold or shared with third parties, and is never used for advertising or profiling.

What's never uploaded

• No audio, ever.
• No name, email, account login, or IP address; no listening / play history.

Because the backup includes your playlists and library structure, it can contain file locations on your Mac (which may include your account folder name). This is your own backup data, kept private to your copy of El Eje and restorable by you; it is never part of the shared, recording-keyed data used to improve the catalog.

Corrections come back to you

The app also receives the database's author-checked corrections for the recordings in your library. You review each one and can accept, reject, or undo it. Your own edits always take priority over a received correction.

Where data is stored

Your backup is sent over HTTPS to the developer's endpoint at el-eje.com and stored on Cloudflare (our hosting and storage provider, acting as our processor).

Your choices

• Consent is required: sharing your edits is part of using the app, so there is no separate on/off switch. If you do not accept the policy at first launch, the app does not run.
• Request deletion: email us with your install's client id (a random token, shown in the app's settings) and we will delete the backup and contributions associated with it.

Bundled data

The tango catalog (titles, orchestras, singers, years, key/BPM, mood tags, tandas, lyrics and translations, and the acoustic fingerprints used for recognition) ships inside the app. It is not personal data and is not collected from you.

Contact: kazemipour.a@gmail.com. If this policy changes, the "Last updated" date above will change and the app will ask you to review it again.