CoinPayments wallet supports 1190 different altcoins (including ERC20), to see the full list click here. The CoinPayments wallet is completely free for non-commercial applications. Merchants using the checkout system and API’s are charged a small 0.50% fee on incoming transactions which is deducted during payment. If merchants or users wish to convert coins on the platform, e.g. BTC-LTC, the conversion rate will be established by the following formula - coin TX fee + conversion partner's fees.