diff --git a/modules/crm_tools/decoupled_auth_crm_tools.info.yml b/modules/crm_tools/decoupled_auth_crm_tools.info.yml
new file mode 100644
index 0000000..5d032b3
--- /dev/null
+++ b/modules/crm_tools/decoupled_auth_crm_tools.info.yml
@@ -0,0 +1,8 @@
+name: Simple CRM Tools
+description: "Tools for building CRM modules."
+core: 8.x
+type: module
+package: Tool
+
+dependencies:
+  - decoupled_auth
diff --git a/modules/crm_tools/decoupled_auth_crm_tools.module b/modules/crm_tools/decoupled_auth_crm_tools.module
new file mode 100644
index 0000000..c1e4b27
--- /dev/null
+++ b/modules/crm_tools/decoupled_auth_crm_tools.module
@@ -0,0 +1,40 @@
+<?php
+
+/**
+ * @file
+ * Simple implementation of Decoupled User Authentication Tools for CRM.
+ */
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\ContentEntityBase;
+
+/**
+ * Implements hook_entity_presave().
+ *
+ * Update status log fields.
+ */
+function decoupled_auth_crm_tools_entity_presave(EntityInterface $entity) {
+  if (!$entity instanceof ContentEntityBase) {
+    return;
+  }
+
+  // Check for status log fields.
+  foreach ($entity->getFieldDefinitions() as $field_name => $definition) {
+    /* @var \Drupal\Core\Field\FieldDefinitionInterface $definition */
+    if ($definition->getType() == 'status_log') {
+      $source_field = $definition->getFieldStorageDefinition()->getSetting('source_field');
+
+      $value = $entity->{$source_field}->value;
+      $original_value = $entity->original->{$source_field}->value;
+      if ($value !== $original_value) {
+        $values = [
+          'value' => $value,
+          'previous' => $original_value,
+          'uid' => \Drupal::currentUser()->id(),
+          'timestamp' => \Drupal::time()->getRequestTime(),
+        ];
+        $entity->{$field_name}->appendItem($values);
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/modules/crm_tools/src/Plugin/Field/FieldFormatter/StatusLogFormatter.php b/modules/crm_tools/src/Plugin/Field/FieldFormatter/StatusLogFormatter.php
new file mode 100644
index 0000000..725ae53
--- /dev/null
+++ b/modules/crm_tools/src/Plugin/Field/FieldFormatter/StatusLogFormatter.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace Drupal\decoupled_auth_crm_tools\Plugin\Field\FieldFormatter;
+
+use Drupal\Component\Datetime\DateTimePlus;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\user\Entity\User;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Defines the 'status_log_list' field formatter.
+ *
+ * @FieldFormatter(
+ *   id = "status_log_list",
+ *   label = @Translation("Status Log (list)"),
+ *   field_types = {
+ *     "status_log"
+ *   }
+ * )
+ */
+class StatusLogFormatter extends FormatterBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings) {
+    parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $label, $view_mode, $third_party_settings);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $plugin_id,
+      $plugin_definition,
+      $configuration['field_definition'],
+      $configuration['settings'],
+      $configuration['label'],
+      $configuration['view_mode'],
+      $configuration['third_party_settings']
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    // @todo Add human readable labels.
+    $elements = [];
+    foreach ($items as $delta => $item) {
+      /* @var \Drupal\decoupled_auth_crm_tools\Plugin\Field\FieldType\StatusLog $item */
+      $values = $item->getValue();
+      if (is_array($values) && !empty($values['value'])) {
+
+        $elements[$delta]['value'] = [
+          '#type' => 'html_tag',
+          '#tag' => 'p',
+          '#attributes' => ['class' => []],
+          '#value' => $this->t('@time: Status was changed from %status_old to %status_new by @username.', [
+            '%status_new' => $values['value'],
+            '%status_old' => $values['previous'],
+            '@time' => DateTimePlus::createFromTimestamp($values['timestamp'])->format('Y-m-d H:i:s'),
+            '@username' => User::load($values['uid'])->label(),
+          ]),
+        ];
+
+      }
+    }
+
+    return $elements;
+  }
+
+}
diff --git a/modules/crm_tools/src/Plugin/Field/FieldType/StatusLog.php b/modules/crm_tools/src/Plugin/Field/FieldType/StatusLog.php
new file mode 100644
index 0000000..87a385e
--- /dev/null
+++ b/modules/crm_tools/src/Plugin/Field/FieldType/StatusLog.php
@@ -0,0 +1,168 @@
+<?php
+
+namespace Drupal\decoupled_auth_crm_tools\Plugin\Field\FieldType;
+
+use Drupal\Component\Utility\Random;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemBase;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\TypedData\DataDefinition;
+
+/**
+ * Plugin implementation of the 'status_log' field type.
+ *
+ * @FieldType(
+ *   id = "status_log",
+ *   label = @Translation("Status log"),
+ *   description = @Translation("Logs changes to a status"),
+ *   default_widget = "string_textfield",
+ *   default_formatter = "status_log_list"
+ * )
+ */
+class StatusLog extends FieldItemBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultStorageSettings() {
+    return [
+      'max_length' => 255,
+    ] + parent::defaultStorageSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
+    // Prevent early t() calls by using the TranslatableMarkup.
+    $properties['value'] = DataDefinition::create('string')
+      ->setLabel(new TranslatableMarkup('Status'))
+      ->setRequired(TRUE);
+
+    $properties['previous'] = DataDefinition::create('string')
+      ->setLabel(new TranslatableMarkup('Previous Status'));
+
+    $properties['timestamp'] = DataDefinition::create('timestamp')
+      ->setLabel(new TranslatableMarkup('Changed timestamp'))
+      ->setRequired(TRUE);
+
+    $properties['uid'] = DataDefinition::create('integer')
+      ->setLabel(new TranslatableMarkup('User responsible for change'));
+
+    return $properties;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function schema(FieldStorageDefinitionInterface $field_definition) {
+    return [
+      'columns' => [
+        'value' => [
+          'type' => 'varchar',
+          'length' => (int) $field_definition->getSetting('max_length'),
+        ],
+        'previous' => [
+          'type' => 'varchar',
+          'length' => (int) $field_definition->getSetting('max_length'),
+        ],
+        'timestamp' => [
+          'type' => 'int',
+        ],
+        'uid' => [
+          'type' => 'int',
+        ],
+      ],
+      'indexes' => [
+        'value' => ['value'],
+        'previous' => ['previous'],
+      ],
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getConstraints() {
+    $constraints = parent::getConstraints();
+
+    if ($max_length = $this->getSetting('max_length')) {
+      $constraint_manager = \Drupal::typedDataManager()->getValidationConstraintManager();
+      $constraints[] = $constraint_manager->create('ComplexData', [
+        'value' => [
+          'Length' => [
+            'max' => $max_length,
+            'maxMessage' => t('%name: may not be longer than @max characters.', [
+              '%name' => $this->getFieldDefinition()->getLabel(),
+              '@max' => $max_length
+            ]),
+          ],
+        ],
+      ]);
+    }
+
+    return $constraints;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function applyDefaultValue($notify = TRUE) {
+    parent::applyDefaultValue($notify);
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function generateSampleValue(FieldDefinitionInterface $field_definition) {
+    $random = new Random();
+
+    $values['value'] = $random->word(mt_rand(1, $field_definition->getSetting('max_length')));
+    $values['previous'] = $random->word(mt_rand(1, $field_definition->getSetting('max_length')));
+    $values['uid'] = mt_rand(0, 1);
+    $values['timestamp'] = mt_rand(1262055681, 1262055681);
+
+    return $values;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function storageSettingsForm(array &$form, FormStateInterface $form_state, $has_data) {
+    $elements = [];
+
+    $elements['max_length'] = [
+      '#type' => 'number',
+      '#title' => t('Maximum length'),
+      '#default_value' => $this->getSetting('max_length'),
+      '#required' => TRUE,
+      '#description' => t('The maximum length of the field in characters.'),
+      '#min' => 1,
+      '#disabled' => $has_data,
+    ];
+
+    // @todo Make this field a select field of existing fields on entity.
+    $elements['source_field'] = [
+      '#type' => 'textfield',
+      '#title' => t('Source Field'),
+      '#default_value' => $this->getSetting('source_field'),
+      '#required' => TRUE,
+      '#description' => t('The field that stores the status being logged.'),
+      '#disabled' => $has_data,
+    ];
+
+    return $elements;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isEmpty() {
+    $value = $this->get('value')->getValue();
+    return $value === NULL || $value === '';
+  }
+
+}