A HEX/ETH "referral" contract that takes an erc20 token address (made for HEX, but any should work), a set of splitter addresses and their percentages. It will split ETH and ERC20 tokens by the addresses' percentages

ReferralContract.sol

pragma solidity ^0.5.12;

import "./HEX.sol"; // TODO: Windows file separator

contract ReferralSplitter {

    event DistributedShares(
        uint40 timestamp,
        address indexed memberAddress,
        uint256 amount
    );

    HEX internal hx;

    address payable[] internal splitAddresses;
    uint8[] internal splitPercentages;

    constructor (address hexContract, address payable[] memory addresses, uint8[] memory percentages)
    public
    {
        require(hexContract != address(0), "HEX contract address required");
        require(addresses.length > 0 && percentages.length == addresses.length,
        "Addresses and percentages must have the same length > 0");
        uint hundred = 100;
        for(uint i = 0; i < percentages.length; i++){
            hundred -= percentages[i];
            if(hundred < 0){
                require(false, "Percentages exceed 100");
            }
        }

        if(hundred != 0){
            require(false, "Percentages must equal 100");
        }

        hx = HEX(hexContract);
        splitAddresses = addresses;
        splitPercentages = percentages;
    }

    function distribute ()
    public
    {
        // eth part
        uint256 balance = address(this).balance;
        uint256 onePercent;
        uint256 share;
        uint len = splitAddresses.length;
        if(balance > 99){
            onePercent = balance / 100;

            for(uint i = 0; i < len; i++){
                if(i == len - 1){
                    share = balance;
                } else {
                    share = splitPercentages[i] * onePercent;
                    balance -= share;
                }

                splitAddresses[i].transfer(share);
            }
        }

        // hex part
        balance = hx.balanceOf(address(this));
        if(balance > 99){
            onePercent = balance / 100;

            for(uint i = 0; i < len; i++){
                if(i == len - 1){
                    share = balance;
                } else {
                    share = splitPercentages[i] * onePercent;
                    balance -= share;
                }

                hx.transfer(splitAddresses[i], share);
            }
        }
    }

    // for testing
    function donate()
    external
    payable
    {}
}