So I've found the right script for FreeBitCo.in
Check it bellow.

var minValue = 0.00000001;
var maxLoss = 0.0000001;
var aimedProfit = 0.000005;
var maxOps = 50;

// Don't touch anything after this
var endResult = 0;
var ops = 0;

// Bets a given amount on a given button and returns the value ot the callback
var bet = function(value, button, callback) {
    var buttonName = button ? 'lo' : 'hi';
    // We use site's api
    $.get('?op=double_your_btc&m=' + buttonName + '&stake=' + value + '&multiplier=2&jackpot=0', function(result) {
            var splittedResult = result.split(':');
            // We update the account balance, as we have it juste there
            $('#balance').html(splittedResult[3]);
            // We finally call the callback
            callback(value, button, splittedResult[1] === 'w');
        }
    );
};

// Main Martingale's method
var martingale = function(value, button, result) {
    // We apply Martingale algorithm
    if (result || (value >= maxLoss && maxLoss !== 0)) {
        button = !button;
        newValue = minValue;
    }
    else
        newValue = 2 * value;
    // We compute new final result
    if (result)
        endResult += value;
    else
        endResult -= value;
    // We start over (and log misc data)
    console.log((result ? '+' : '-') + value);
    ops++;
    if ((ops < maxOps || maxOps === 0) && (endResult < aimedProfit || aimedProfit === 0))
        bet(newValue, button, martingale);
    else {
        console.log('Martingale finished in ' + ops + ' operations!');
        console.log('Result: ' + endResult);
    }
};

// Init operation
martingale(minValue, false, false);