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

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 will be supported later this year)

1. Disconnect AK from PC
2. Download the filetransfer driver at Android File Transfer site.
http://www.android.com/filetransfer
3. Install the file downloaded according to the attached guide in pdf.
4. Use AK after connection with PC.

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.

i. Customers should contact the point of purchase within seven days of purchase for aftersales service. The service thus is under the decision and liability of the party which the customer has made the purchase. ECT is NOT liable for the actions taken and reserves the right to provide replacement or service of any kind.

ii. ECT does NOT provide on door services of any kind.

iii. ECT will NOT bear any of the logistics cost within the warranty period.

iv. Should the product falls out of the warranty period, the customer have to bear all the logistics cost involved if the customer wishes to receive warranty service of any kind.

v.The warranty for the Ultrasone Edition Series is 5 years. The first year of the warranty will include parts and repair. Starting from the second year, the warranty will only cover the parts for repair. Additionally, an inspection fee of HKD 500 and 10% of the retail price will be charged for repair. Should the customer confirm reparation after inspection, the inspection fee will be deducted from the repairing fee. The inspection fee will NOT be returned under any circumstances.
*Artificial damage, modifications to the headphone and accessories such as, but not limited to, cables, headband, ear-pads, ear-cups are not included in the warranty.

vi. The warranty for Audeze headphones drivers is 3 years. The first year of the warranty will include parts and repair. Starting from the second year, the warranty will only cover the parts for repair. Additionally, an inspection fee of HKD 500 and 10% of the retail price will be charged for repair. Should the customer confirm reparation after inspection, the inspection fee will be deducted from the repairing fee. The inspection fee will NOT be returned under any circumstances.
*Artificial damage, modifications to the headphone are not included in the warranty.