Caution of installing 3rd part apps
The source of apps listed is unknown and not provided by Astell&Kern. Please be aware that if any app is installed, the device may be damaged and personal data compromised. If you install an app from an unknown source, despite the warning, Astell&Kern and ECT is not responsible for any damages to the device and data resulting from the app's installation, and downloading and installing such apps may limit the scope of after-sales services provided by Astell&Kern.

Installation of any app is under the discretion of the user.
Which streaming platforms can be used on AK players?
The below streaming platforums can be installed in AK DAP models that supports OpenAPK:

Amazon music / Spotify / Tidal / Sound Cloud / Pandora / Melon / Bugs / Music Mate / AWA / QQ Music / KK BOX

16/10/2018 update - adding the below:
Sirius MX / Tune-In / myTuner / KT genie / bandcamp / Joox / Moov
Which Astell&Kern DAP can allow streaming via OpenAPK services?
The below Astell&Kern DAP allow streaming via OpenAPK services:

A&Ultima SP1000, SP1000M, A&futura SE100 (Normal and M.Chat special version), A&norma SR15
How to connect my AK player to my OSX devices?
1. Disconnect AK from PC
2. Download the filetransfer driver at Android File Transfer site.
3. Install the file downloaded according to the attached guide in pdf.
4. Use AK after connection with PC.
Where can I download the drivers/firmware/manual of my product?
The Drivers/Firmware/Manual, if any, will be available on the download page of the corresponding product. Please visit the product page of your product to download the latest drivers/firmware/manual.