It doesn't make sense to me to store a 24 word seed on an (always offline) mobile.
If your goal is to have a full offline backup, why not store it on paper? Or an USB-stick / SD card ?
There is way too much 'technology' in a mobile to be 100% sure its completely offline.
Especially for backing up information in form of 24 words.
If you want to increase the security of your offline backup, then use a simple storage device and encrypt your seed phrase with a pin/password.
Even better would be a (correctly generated) paper wallet or a hardware wallet. Those two would give you the 'highest grade' of security.
If your goal is to have a full offline backup, why not store it on paper? Or an USB-stick / SD card ?
There is way too much 'technology' in a mobile to be 100% sure its completely offline.
Especially for backing up information in form of 24 words.
If you want to increase the security of your offline backup, then use a simple storage device and encrypt your seed phrase with a pin/password.
Even better would be a (correctly generated) paper wallet or a hardware wallet. Those two would give you the 'highest grade' of security.
Got to agree with Bob here. There's too much I don't know about a lot of devices to trust them completely. Unless technology's really advanced beyond the human propensity for negligence, I recall it's even possible to clone a phone via Bluetooth or some other wireless method (I know this doesn't mean 100% offline, but for most people online simply means connected to Internet). Most corner shops in my country also can unlock a pin protected phone in minutes.
This also doesn't take into account the average lifespan of mobile storage, which simply isn't built to last as long as an actual device built for data storage.
