Security

Security apps are a natural fit for open source, because you can check what the code does. Most entries here are VPN clients: WireGuard, Mullvad VPN, Proton VPN, IVPN, Outline and Passepartout for OpenVPN. Lockdown is a firewall that blocks trackers at the network level, and Orbot and iCepa route traffic through Tor.

Keybase, Tutanota and Proton Mail cover encrypted messaging and email, and Prey tracks lost or stolen devices. Tofu Authenticator handles two-factor codes, SimpleLogin creates email aliases, and LegitURL scans links offline. Password managers have their own subcategory. Most of these apps are maintained and on the App Store, and most use GPL licenses. VPN apps rely on Network Extension entitlements, which you need to request from Apple before you can ship a fork.