Moneromooo has kindly added an optional user supplied entropy to his offline wallet generator available at moneroaddress.org. So now it's possible to use it with Monero coin IDs (+ a password for more security) to create a new cold storage associated with it. There is a field Custom entropy. Just fill in your coin IDs and a password, for example: 1Fe58dA D7auQk6 your_password and click Generate wallet! For additional security you can download the source code from original repository and do it locally at offline computer.Is it safe to use custom entropy?
Yes, it can be safe if used properly. Cryptonic base58 coin IDs generated randomly in accordance with proposed standard for physical coins that may represent funds on the Monero network. They have ~81 bits of entropy. To increase the security and minimize risks please use a strong password or passphrase together with coins IDs and do not expose it as well as your coin IDs. You can also choose your own way of entering coin IDs mixed with your own passphrase(s) in any order as you like in custom entropy field. Just memorize it well or right down securely! More detailed explanation can be found in this discussion.Do I need cryptonic site to create or access the Monero wallet?
No. With a help of the offline wallet generator, your coin IDs + password is your deterministic key to create or restore a Monero wallet.What is the validation of Cryprocoins?
If you click Validate Cryptocoin and fill in the coin IDs you will get information about this coin (its features, total number of coins in this batch and the date of production).