Second Brain, a personal Android app by JAC's Ventures LLC. Last updated 2 November 2026.
Everything you type into Second Brain (ideas, tasks, reminders, lists, notes and project notes) is stored on your phone. There is no Second Brain server and no account with us.
When you capture something, or ask the app a question, the text you typed (and, for questions, a small part of your notes) is sent to Anthropic's Claude service so it can be sorted or answered. This uses your own Anthropic API key. If that service can't be reached, the app sorts the text on the phone instead.
If you connect Google Drive, the app saves a daily backup copy of its data to your own Google Drive,
in a folder called "Second Brain Backups", and keeps the last 7 copies. It asks only for the
drive.file permission, so it can see and change only the files it created itself. It cannot
see any other file in your Drive.
The backup files go straight from your phone to your Drive. We never receive them.
Second Brain's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
No ads, no tracking, no analytics. Your data is never sold or shared with anyone, and it is not used for anything other than running the app for you.
Uninstalling the app removes the data on the phone. To remove the backups, delete the "Second Brain Backups" folder in Google Drive. You can also remove the app's Drive access at any time at myaccount.google.com/connections.