I just wanted to share something I've been using for HIFI on the go for anyone who cares. Since its safe to say that everyone owns a smart device nowadays, it makes sense to take advantage of its processing power instead having to buy a separate DAP/DAC/AMP to carry around for our HIFI audio needs.
On iOS, there are a couple of dependable options to play lossless audio. The native iOS Music app is capable of playing back Apple lossless (ALAC) files which you manage through iTunes on the PC/Mac. You can convert your CDs into ALAC files and sync them to your iOS device.
Your second option is to download the VideoLAN Cross-Platform player (VLC). I like this option because it's compatible with a lot more lossless formats like WAV and FLAC. (One caveat is in the rare case you have a file with a sample rate of 192khz, the iPhone doesn't seem to have enough processing power to play it back.)
On Android devices, I've only used VLC player. I'm not sure if there are other players out there that can play back lossless files.
Apple iDevices and most Android devices have a native playback rate of 16bit:44.1khz.
Extended Sample Rate Playback and Amplification:
There are plenty of iOS/Android DAC/AMPs available in the market. I've had the opportunity to try a few of them. These devices override the onboard audio processing of your mobile device. Here are a few examples of DAC/AMPs for mobile devices.
1. I personally own and use the Nexum AQUA. They manufacture individual versions of this device for iOS and Android. It retails for about $90USD and connects via the iOS Lightning port or microUSB on Android. The AQUA is a 24bit:192khz DAC/AMP. I can power most of my headphones with this device with the exception of my 600 ohm Beyerdynamic DT880 Pro.
2. The AudioQuest Dragon Fly is a small USB stick DAC/AMP that comes highly recommended. It comes in three flavors with varying specs. They are compatible with both iOS and Android devices. iOS device owners have to purchase an adaptor with an Apple Authentication chip.
Apple USB Adapter: Amazon http://a.co/fY7jQ5j
3. A company called Cozoy makes a number of DAC/AMPs for iOS and Android devices. Their flagship model is called the Cozoy REI. It is a 32bit:384khz DAC/AMP. I believe this is 32bit floating point, although I'm not sure. They also recommend a propriety (Relisten) media player if you want to take advantage of the on-board DSP enhancements. This is the most expensive of the bunch, retailing at $550USD, but it also is the most robust in-terms of its capabilities and features.