DevDocs App

Considered to be one of the best alternatives for the illustrious Dash app, DevDocs.io is a useful web app that provides its visitors with instant access to reference manuals for almost all libraries and front-end languages, as well as to APIs and their official documentation in a single-page format.
It's available as a Sublime Text and Brackets plugin, and it's also available as a Chrome extension, but unfortunately, there is no official desktop client.
However, thanks to the mighty Electron app, you can now access the full functionality of DevDocs without having to use a web browser and directly on your computer's desktop thanks to an unofficial client dubbed DevDocs App.

Brings DevDocs.io to your computer's desktop in just a few seconds

Deploying DevDocs App on your computer, only requires you to launch its installer. You can then sit back and relax while it automatically takes care of everything for you.
If you have ever used the DevDocs web app before, then you should have no problems whatsoever, since the wrapper allows you to take advantage of all the available features, easily accessible from the same slick and responsive interface.

API documentations for almost all programming languages, now accessible without a web browser

You get the same impressive support for a dozen programming languages and their APIs. For example, C, C++, CoffeeScript, CSS, DOM, Git, HTML, HTTP headers and status codes, JavaScript, jQuery, Markdown, PHP, Python, React, Ruby, SVG and much more.
As expected, you can also fetch various documents that are not currently displayed, but you will need Internet access, mind you. Searching for documents and navigating within them is quite straightforward as each set if displayed in expandable tree-like structures.

Smooth-running DevDocs unofficial client

To conclude, If you are sick and tired of having tons of separate browser tabs with documentation content and you want to be able to access DevDocs from a distraction-free environment, then DevDocs App is surely worthy of your attention since it's currently the only wrapper for DevDocs at this time.