A simple token (not ERC20 compliant)

SimpleToken.sol

pragma solidity ^0.4.24;

contract SimpleToken {
    string public constant name = "My Simple Token";
    string public constant symbol = "TEST";
    uint8 public constant decimals = 18;    // same as ether
    
    mapping (address => uint256) public balanceOf;

    event Transfer(address indexed from, address indexed to, uint tokens);
    
    constructor() public {
        balanceOf[msg.sender] = 10 ether;
    }

    function transfer(address to, uint256 value) public returns (bool success) {
        require(balanceOf[msg.sender] >= value, "Not enough tokens");
        require(value > 0, "Zero transfer");
        require(balanceOf[to] + value > balanceOf[to], "Overflow");
        balanceOf[msg.sender] -= value;
        balanceOf[to] += value;
        emit Transfer(msg.sender, to, value);
        return true;
    }
}