Repeated keystroke "w" for Agar.io
Karabiner:

  &lt;item&gt;
    &lt;identifier&gt;private.w2wRepeat&lt;/identifier&gt;
    &lt;name&gt;Turn W key to W key repeat&lt;/name&gt;
    &lt;autogen&gt;
      __KeyToKey__
      KeyCode::W,
      KeyCode::W,
      DelayUntilRepeat::RawValue::1,
      KeyRepeat::RawValue::1,
    &lt;/autogen&gt;
  &lt;/item&gt;