Here, I am very grateful to you for your interest in our DAPP. Here are some common questions that I hope will help you:
Because it's a safe way, you don't need to transfer tokens to our smart contract directly, and the approval option just grant permission for smart contract to spend up some amount, it's only available when you actually send a token transfer by our contract, so you don't worry about it, just do it. About ERC20 Token Standard#Approve
No, you don't have to, in my suggestion, you can approve a large amount to smart contract in one time, that you can save some time and tx fees.
This is caused by the Ethereum's gas limit. Due to the special nature of your token contract, you can change the send address number per tx to 150, and you will succeed.
Please check if your token smart contract has the following similar code, if so, Just click Reset Aproval Amount, and then, approve again.
if ((_value != 0) && (allowed[msg.sender][_spender] != 0)) throw
function approve(address _spender, uint _value) {
// To change the approve amount you first have to reduce the addresses`
// allowance to zero by calling `approve(_spender, 0)` if it is not
// already 0 to mitigate the race condition described here:
// https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
if ((_value != 0) && (allowed[msg.sender][_spender] != 0)) throw;
allowed[msg.sender][_spender] = _value;
Approval(msg.sender, _spender, _value);
}
You must make sure you have install MetaMask(https://metamask.io) and unlock the right account.
The default number is 175, the max number is 200. This depends on the gas limit of Ethereum. If it is too large, the transaction may fail. 175 is the number we have tested with a high success rate. If you still often fail, try to reduce this number.
The default tx fee is 0.01ETH, But we have VIP membership, you just need to pay 1 ETH to be a VIP, the tx fee will be zero forever for your account.
Sure, you can check them by the following link.
Mainnet: https://etherscan.io/address/0x2f6321db2461f68676f42f396330a4dc4a8f49df#code
Ropsten: https://ropsten.etherscan.io/address/0xfe25a97b5e3257e6e7164ede813c3d4fbb1c2e3b#code