All dark web websites has .onion Top Level Domain and to resolve that we requires TOR browser.
For android mobile you can download any of the application from play store to access dark web:
Orfox: Tor Browser for Android - Android Apps on Google Play
Orbot: Proxy with Tor - Android Apps on Google Play
Fire.onion (Browser + Tor) - Android Apps on Google Play
VPN+TOR+Cloud VPN Globus Pro! - Android Apps on Google Play
DuckDuckGo Search & Stories - Android Apps on Google Play
But I think Orfox and Orbot is better because it also available for windows mobiles:
#Download Orfox from play store
Orfox is built from the same source code as Tor Browser (which is built upon Firefox), but with a few minor modifications to the privacy enhancing features to make them compatible with Firefox for Android and the Android operating system.
But the Orfox requires Orbot app for Android to connect to the Tor network. So download Orbot app and install it.
Orbot is a free proxy app that empowers other apps to use the internet more securely. Orbot uses Tor to encrypt your Internet traffic and then hides it by bouncing through a series of computers around the world. Tor is free software and an open network that helps you defend against a form of network surveillance that threatens personal freedom and privacy, confidential business activities and relationships, and state security known as traffic analysis.
After installing Orfox and Orbot you are able to access Dark web. if you wana know what dark web is and all about , follow me 