Are there any Wallet Apps, that are like "cold wallets"?

Hey, since cold wallets don't seem to be so secure I was wondering... Is there an open source Wallet for Android, that can't connect to anything, and only generate seeds and send funds.

Since I use GrapheneOS, I feel kind of safe about everything stored on my phone, especially since I can sandbox my wallet from all of my softwares.

So I would have an actualy secure wallet, that is on my phone.