Once you have Krux installed on it, you'll never need to plug it into a computer again
If you can't plug it into a computer then how exactly do you think you are going to be able to do transactions? Does this thing have an internet connection or something?
It's fully airgapped. No internet. No wifi or bluetooth.
An airgapped hardware wallet communicates with apps using QR codes.
The benefit of using an airgapped device is that it has no connection to the internet, which means hackers can't reach your keys, which means hackers can't steal your coins. And the benefit of using an airgapped hardware wallet with a large screen is that it shows you what you're signing.
In my opinion, moving Bitcoin this way is much safer.
Let's say you're using BlueWallet, which is probably the easiest to use open source wallet app (it has a great design. Super simple. Sparrow is great too though). You'll create a transaction in BlueWallet ("move 0.01 BTC to
this address"). BlueWallet will make a QR code with a request for your hardware wallet to scan (generated from details of your transaction). You'll scan it with Krux. Krux will use that data with your keys to generate a QR signature. You'll scan that signature with BlueWallet.
Scan the BlueWallet request with Krux.
Scan the Krux signature with BlueWallet.
Done.
The great thing about Bitcoin transaction signatures is that a signature is only valid for that specific transaction. So, if your phone or your computer is hacked, the hacker can't change the signature or change the address to send your coins to his wallet, because any change to the signature would mean the signature wouldn't be valid for the transaction anymore, which means the transaction would fail... which means your coins would stay safe & sound at your address.
The "crypto" part of cryptocurrency stands for Cryptography. Bitcoin signatures are a brilliant form of cryptography that proves you have the keys without revealing what your keys are. It's math. Brilliant, brilliant math.
Another great thing about Krux is that it makes using Testnet easy. Testnet is literally a testing version of Bitcoin where the coins have no value, because it's just for testing. You can go to a testnet faucet site & get free testnet coins, and then literally play with different options for setting up security however you want.
Want to try multisig? Do it first with testnet.
Want to try using a strong passphrase? Testnet!
Want to mess with BIP85 (which I love and highly recommend to anyone who understands how seed phrases work)? Hooray for testnet!
Testnet is awesome.