Privacy Policy

Effective date: October 27, 2026

This Privacy Policy explains how Mistblue (an independent software developer; “we” or “us”) handles information on listenflow.mistblue.dev (the “Site”) and in the waitlist emails we send.

1. Who we are

Mistblue, an independent software developer based in Japan, is responsible for the information described here (the “controller”).
Contact: [email protected]
We will promptly provide the operator’s name and address upon request to the contact address above.

2. Information we collect

Information you enter in the waitlist form

  • Your email address
  • Your operating system (Windows / macOS / Both, as you select it)
  • The language of the page you signed up from (Japanese / English)
  • The date and time you signed up

Information related to our emails

  • Records of our emails being delivered, and of unsubscribes

Email opens and link clicks are counted only in aggregate; we do not record them for individual recipients.

Information we process to prevent abuse

  • Your IP address and technical information about your browser, used for verification by Cloudflare Turnstile
  • For rate limiting, a value derived from your IP address using a one-way function with a secret value, together with a submission count. These records are set to expire 10 minutes after they were last written. We do not store your IP address itself

If you contact us

  • Your email address and the content of your message

Stored in your browser

  • Your theme preference (dark/light) is stored in your browser (localStorage). It is never sent to us

We use Cloudflare Web Analytics to count page views and see where visitors come from. It does not use cookies, and we do not use it to identify individuals. The Site does not use advertising trackers.

Purpose Legal basis (where the GDPR applies)
Sending updates about ListenFlow, including release announcements, and occasionally about related Mistblue products Your consent
Tailoring updates by operating system and language (for example, telling you when the macOS version is released) Your consent
Sending a welcome email after you sign up Your consent
Preventing spam and abusive signups Our legitimate interest in keeping the waitlist free of abuse
Responding to your inquiries Our legitimate interest in answering you
Counting visits to the Site (Cloudflare Web Analytics) Our legitimate interest in understanding how the Site is used

You can withdraw your consent at any time by unsubscribing. This does not affect anything we did before you withdrew it.

Providing your email address is not a legal or contractual requirement, but without it we cannot send you updates.

We do not make decisions about you based solely on automated processing.

4. Welcome email

When you sign up, we send you one welcome email. If you did not sign up yourself, please use the unsubscribe link in that email, and you will not receive any further updates.

5. Service providers and international transfers

We use the following service providers.

Brevo (Brevo SAS, France)

  • Information: email address, operating system, language, signup date and time, and email delivery records
  • Purpose: storing signups and sending the welcome and update emails
  • Location: Brevo states that it hosts its databases on servers in the EU (France, Germany and Belgium). Its affiliates and subprocessors located elsewhere, such as in the United States and India, may access the data for maintenance and support

Cloudflare (Cloudflare, Inc., United States)

  • Information: technical information related to your visit (such as your IP address, the pages you view and the referring site), the information submitted through the waitlist form, and information used for Turnstile verification (such as your IP address, browser type and connection characteristics)
  • Purpose: serving the Site, measuring visits, receiving signups and preventing abuse
  • Cloudflare states that it also uses information processed by Turnstile to improve its own bot detection. For that use, Cloudflare acts under its own policy (Turnstile Privacy Addendum)

Because we operate from Japan, your information is processed in Japan as well as in the countries above. The European Commission has recognized Japan as providing an adequate level of data protection. For transfers of personal data from the EEA, the UK or Switzerland to the United States, Cloudflare participates in the EU-U.S. Data Privacy Framework (including its UK and Swiss extensions). Cloudflare’s Data Processing Agreement provides that the European Commission’s Standard Contractual Clauses apply if that certification lapses. Cloudflare is also certified under the Global CBPR and Global PRP systems. You can request more information about these safeguards by contacting us.

6. Sharing

We do not sell your information or share it with third parties, except with the service providers above or where required by law.

7. How long we keep it

  • Signups: until you unsubscribe or ask us to delete your information
  • If we stop sending updates: the whole list is deleted
  • Email delivery records: kept with your signup and deleted when your signup is deleted
  • Inquiries: as long as needed to respond

8. Security

We take measures appropriate for a one-person operation, including:

  • Only the operator handles your information, and only for the purposes above
  • Connections to the Site are encrypted (HTTPS)
  • Credentials for our service providers are kept server-side, and our admin accounts are protected with two-factor authentication
  • The devices we use are kept up to date and screen-locked
  • We review our providers’ terms and safeguards

9. Your rights

Depending on the laws that apply to you, you may have the right to access, correct or delete your information, to restrict or object to its use, and to receive it in a portable format. To make a request, email [email protected] from the address you signed up with. If you write from a different address, we may send a confirmation to your registered address first. We will respond promptly and without charge.

If you are in the EU or the EEA, you also have the right to lodge a complaint with your local data protection authority. You can find yours on the European Data Protection Board website.

10. Unsubscribing

You can unsubscribe at any time using the link included in every update email.

11. About the ListenFlow app

In the ListenFlow app, playback, waveform display and local speech-to-text run entirely on your computer, and your audio and files are never sent to us. Only when you use AI features is data sent directly to an external AI service, using the API key you set up yourself. We will publish details on how the app handles information when the app is released.

12. Changes to this policy

We will post any changes on this page. For significant changes, we will also notify people on the list by email.

13. Contact

Mistblue
Email: [email protected]

Back to ListenFlow