Chart re-implemented and added coveralls and other instructions, which will probably not work at all.

app/Support/Amount.php

@@ -3,6 +3,9 @@
 namespace FireflyIII\Support;
 
 use FireflyIII\Models\Transaction;
+use FireflyIII\Models\TransactionCurrency;
+use Preferences as Prefs;
+use Cache;
 /**
  * Class Amount
  *
@@ -54,4 +57,29 @@ class Amount
         // €
         return $symbol . ' ' . $string;
     }
+
+    /**
+     * @return string
+     */
+    public function getCurrencyCode()
+    {
+        if (defined('FFCURRENCYCODE')) {
+            return FFCURRENCYCODE;
+        }
+        if (Cache::has('FFCURRENCYCODE')) {
+            define('FFCURRENCYCODE', Cache::get('FFCURRENCYCODE'));
+
+            return FFCURRENCYCODE;
+        }
+
+
+        $currencyPreference = Prefs::get('currencyPreference', 'EUR');
+        $currency           = TransactionCurrency::whereCode($currencyPreference->data)->first();
+
+        \Cache::forever('FFCURRENCYCODE', $currency->code);
+
+        define('FFCURRENCYCODE', $currency->code);
+
+        return $currency->code;
+    }
 }

app/Support/Facades/Steam.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace FireflyIII\Support\Facades;
+
+use Illuminate\Support\Facades\Facade;
+/**
+ * Class Steam
+ *
+ * @package FireflyIII\Support\Facades
+ */
+class Steam extends Facade
+{
+    /**
+     * Get the registered name of the component.
+     *
+     * @return string
+     */
+    protected static function getFacadeAccessor()
+    {
+        return 'steam';
+    }
+
+}

app/Support/Steam.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace FireflyIII\Support;
+
+use Carbon\Carbon;
+use FireflyIII\Models\Account;
+
+/**
+ * Class Steam
+ *
+ * @package FireflyIII\Support
+ */
+class Steam
+{
+    /**
+     *
+     * @param Account $account
+     * @param Carbon   $date
+     *
+     * @return float
+     */
+    public function balance(Account $account, Carbon $date = null)
+    {
+        $date    = is_null($date) ? Carbon::now() : $date;
+        $balance = floatval(
+            $account->transactions()->leftJoin(
+                'transaction_journals', 'transaction_journals.id', '=', 'transactions.transaction_journal_id'
+            )->where('transaction_journals.date', '<=', $date->format('Y-m-d'))->sum('transactions.amount')
+        );
+
+        return $balance;
+    }
+
+}