If someone wants quick wallet options wouldn't it be something like Coinomi even better option then any website that can disappear tomorrow?
Nothing is stored it will all happen in your browser. You can use it local if you dont trust the source where it is hosted.
As the github says: 'The code is based on coinb.in, forked form tsbw.io (see
https://tsbw.io) and BTX support was been added.'
'You can enter a compressed or uncompressed WIF key as your passphrase; this means you can use the same wallets you have at
https://coinb.in or any other wallet that allows exporting in this format.'
Brain wallets are never considered safe, Its the purpose your going to use them for if you can consider it safe enough.
You will not make a paper wallet and generate it online and use it long term or with high amounts
https://walletgenerator.net/?currency=BitcoreI pointed this site out because i use it for the puzzle and it is a easy way to verify keys and can be used as a quick wallet solution.