Online Shop is described as 'Turn your idea or physical business into an online e-commerce store with powerful features and functionality, increasing sales and revenue with no monthly fees!' and is an app in the Business & Commerce category. There are more than 100 alternatives to Online Shop for a variety of platforms, including Online / Web-based, Self-Hosted solutions, Windows, SaaS and Linux. The best alternative is Etsy. It's not free, so if you're looking for a free alternative, you could try PrestaShop or WooCommerce. Other great apps like Online Shop are Squarespace (Paid), Wix (Freemium), ISPmanager (Paid) and Thirty Bees (Free, Open Source).
CubeCart is a hugely popular and very established open source eCommerce solution. A fantastic shopping cart which is easy to install, with a committed group of forum members eager to answer any CubeCart question.