Yes, there are software wallets that can be used to store Bitcoin on a flash drive or other storage device. These wallets are often referred to as "cold wallets" or "offline wallets" because they are not connected to the internet, which provides an additional layer of security against potential hacks or cyber attacks.

One example of a software wallet that can be used to store Bitcoin on a flash drive is Electrum. Electrum is a popular Bitcoin wallet that can be downloaded onto a computer and used to store Bitcoin securely offline. The wallet generates a seed phrase that can be used to recover the wallet in case of loss or theft, and can be encrypted for additional security.

Another option is to use a paper wallet, which involves printing out the private key and Bitcoin address on a piece of paper and storing it in a secure location. However, it's important to note that paper wallets can be vulnerable to damage, loss, or theft, and should be used with caution.

It's important to remember that using any type of wallet, whether hardware or software, comes with its own set of risks and requires careful consideration of security measures. It's recommended that individuals do their research and seek out reputable wallet providers before storing any significant amount of Bitcoin or other cryptocurrencies