It is possible to confirm and reject Safe transactions with the Gnosis Safe Mobile apps. As a prerequisite, you need to import an owner key by importing a seed phrase or directly a raw private key.
Note: When using import via seed phrase, the apps do not store the entire seed phrase, rather just the private key of the account selected. To add multiple accounts from a single seed phrase, you will have to go through the import flow multiple times.
We recommend to always have a device password/PIN set up for additional access control
Signing keys are stored in the native iOS Keychain Services, as recommended by Apple. The keychain ensures that only the Gnosis Safe app can access your keys. Please refer to the Keychain Services Developer Documentation for all details.
We use the access control rule "when unlocked", which means access to the keychain (and thereby the keys) is restricted according to the unlock state of the entire device. The app will only be able to access your keys when the device is unlocked. Consequently this access control does not exist in case you do not have a device PIN/password set up.
We are planning to introdce an app password which users can configure to be used for (1) opening the Gnosis Safe Mobile app and/or (2) signing transactions.