Error on Shop App

Hello,

I've just downloaded and installed the newest version of Perch and the Shop App and I'm receiving this error:

 Parse error: syntax error, unexpected '[' in /home/nathani5/public_html/perch-dev/perch/addons/apps/perch_shop/admin.php on line 7

My diagnostic report is:

    Perch: 2.8.29, PHP: 5.3.28, MySQL: 5.5.49, with PDO
    Server OS: Linux, cgi-fcgi
    Installed apps: content (2.8.29), assets (2.8.29), categories (2.8.29)
    App runtimes: <?php $apps_list = array( 'content', 'categories', // 'perch_blog', // 'perch_members', // 'perch_shop' ); ?>
    PERCH_LOGINPATH: /perch-dev/perch
    PERCH_PATH: /home/nathani5/public_html/perch-dev/perch
    PERCH_CORE: /home/nathani5/public_html/perch-dev/perch/core
    PERCH_RESFILEPATH: /home/nathani5/public_html/perch-dev/perch/resources
    Image manipulation: GD Imagick
    PHP limits: Max upload 128M, Max POST 128M, Memory: 256M, Total max file upload: 128M
    F1: 2edba60ed1f613d6dd804feb202456a2
    Resource folder writeable: Yes
    DOCUMENT_ROOT: /home/nathani5/public_html
    HTTP_HOST: www.nathanieltest.co.uk
    REQUEST_URI: /perch-dev/perch/core/settings/diagnostics/
    SCRIPT_NAME: /perch-dev/perch/core/settings/diagnostics/index.php

I had a look at what's on line 7 of admin.php and it's this...

$this->add_setting('perch_shop_price_tax_mode', 'Prices entered as', 'select', 'exc', [

Any ideas?