Many of us get to use web apps, and lots of them feel the same. Although you feel the difference between Spotify and Facebook, in essence, they share the same premise of working in a browser and helping you play media files. However, at their core, they have very little in common, especially at a developer level. Due to different choices of technologies, the production stage varies depending on the tech stack; and a framework is a backbone of what the product will be in the future. Here's why RoR comes into play.
Whether it's the language simplicity, cost-effectiveness, or scalability, RoR has firmly stepped into the web realm of the Internet and can surely be called one of the main tools for creating large-scale apps. Code reuse is arguably what makes it so good—less code means a faster development cycle and better performance. A vast amount of RubyGems is another factor that gives an edge to RoR when choosing a framework. You get a full package of plugins that serve every purpose to make development easier. This alleviates a sizeable part of the job, allowing devs to focus on making their code clean and capable of running all sorts of apps.
We've condensed a number of apps that took advantage of RoR and gained large popularity among the masses thanks to just being good rather than extensive marketing enforcement. So, these are the products we can't live without.