What's the best second brain app for iPhone that doesn't need an account?
By Taha Baalla·
Drafted with AI from the Nemos app and its documentation. Details about other apps can change, so check their sites.
People usually ask this for one of two reasons: they want less friction, or they do not want their content on someone else's server. Those have different answers.
For content, Nemos keeps your library in your own iCloud rather than on a Nemos server, so a Nemos sign-in does not place your notes with us. Sign-in turns on sync. The library itself comes from your device's iCloud account. AI runs on device by default.
For no sign-in at all, Obsidian is the strong pick. Its notes are plain Markdown files stored on your device, and it needs no account for personal use. It asks for more setup and does not read screenshots or save Reels with previews the way Nemos does.
Apple Notes is the low-effort choice. It needs nothing beyond your Apple ID and syncs through iCloud, although search across links and images is more limited. Pick by what you are protecting: your time, or your data's location. Then compare what each app does with that.