Is there a multi cryptocoin wallet cleint or service? I'm asking because I'm using the www.multipool.us pool and I would like a central client to store the coins. 
you can use bleutrade, but it's an exchange
Never a good idea to store any quantity of coins at an exchange for any length of time
I have tried a few multi-coin wallets
Coinwallet was pretty good, lots of alt coins + POS but recently gracefully closed due to hacking
https://www.cryptonator.com - they have sending fees or the option of a premium account (https://www.cryptonator.com/fees) - if you send dust to your wallets they are unlikely to be credited, I had a pending transaction which took a while to resolve but was eventually dealt with. Havent used them for while. They have a built in Exchange.
https://holytransaction.com a Universal Cryptocurrency Wallet might be worth a look, havent used them for a while, had a couple of minor issues with exchanges using their built in exchange which they resolved very quickly. You can only have one address per wallet.
But in the end they are all centralised and you are at their mercy .