We are using a Multi-Blockchain-API to import coins on the Altcoin Wallet Import page. Nevertheless they do not list all coins.
New coins are added, but please note that we do not have any influence over the listed coins and we can not add specific coins on request into the Altcoin Wallet Import.
If your altcoin is not on the list, we do not offer a wallet import (yet). You can request that they add a certain coin by directly contacting them: chainz.cryptoid.info
Unfortunately, we are not able to integrate wallet imports for cryptocurrencies ourselves, because we would need to implement the whole Blockchain and this is not possible for us.
If your coin is not listed you can enter the transactions either manually on the "Enter Coins" page or with our bulk importers "Excel Import" or "Custom Exchange Import". Both bulk importers are very flexible and customizable and data can be uploaded in a bulk action. It is hopefully possible to extract transaction/trading history from your altcoin wallets as a starting point for those mentioned import options.