Privacy policy
Updated 30 October 2026
Chart Gym is made by Ninh Luong. This page says what the app keeps about you, who else receives it, and how to delete it. Questions: support@chartgym.app.
What Chart Gym keeps
- A random device ID, made by the app, so you can play without an account.
- Your practice: the charts you play, your trades, plans, reasons and notes, what you tell the app about your trading, your messages to the Coach and its replies.
- Your account, if you sign in: the ID Apple or Google gives us and your email address (with Apple, it may be a private relay address), or the email address you sign in with.
- How the app is used: when it opens, when you step through a chart, which screens you open, and errors when a chart fails to draw. These help fix problems and see where people get stuck.
- Your subscription status, if you subscribe. Apple handles the payment; we never see your card.
Chart Gym has no ads, does not track you across other apps or websites, and does not sell your data.
Who else receives it
- Fireworks AI runs the AI model behind the Coach. When the Coach replies, it receives your practice and messages to write that reply. Fireworks AI is a US company. It does not keep them or use them to train AI models.
- Railway (US) hosts the server and database where your data is stored.
- PostHog (US) may receive how the app is used, as listed above, to show us where people get stuck. It never receives your trades, notes or messages to the Coach.
- Brevo sends your sign-in code when you sign in with email, so it receives your email address.
- Apple and Google, when you sign in with them, under their own privacy policies.
How long it is kept, and deleting it
Your data is kept while you use Chart Gym. Delete your account in the app and everything above is deleted from our database, including your Coach history; if you signed in with Apple, we also revoke Chart Gym's access to your Apple ID. You can also email support@chartgym.app and we will delete it for you. You can download your practice record as a spreadsheet from the app.
Children
Chart Gym is not meant for children under 13, and we do not knowingly collect their data.
Changes
If this policy changes, the date above changes with it.