LeTV S50 (Air) installs the application market through U disk
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Installation process 1 Download the sofa butler installation file → 2U disk to connect the TV → 3 TV to enter the file management → 4 read the U disk file → 5 Installation is complete
Steps
1. Baidu search for "sofa manager" into the sofa network, download the sofa butler package; or directly click the link (http://app.shafa.com/shafa.apk) to download the sofa butler package. 
Copy the downloaded apk installation package to the U disk.
(Note: If the U disk can not read the installation package file, you need to change the sofa installation package file name suffix (example: com.shafa.market_3.1.0.apk) to uppercase (example: com.shafa.market_3.1.0. APK), please change the file name suffix on the computer, then copy it into U disk)
2. Insert U disk into LeTV. A prompt box will pop up. Select "View all". Users without this dialog box can find "File Management" and then enter U disk. 
3, from the U disk to find just downloaded the sofa butler package, click to complete the installation. 
If you still can not read the U disk, it is recommended to format the U disk to FAT32 format (if there are other contents in the U disk, export and then format), or try another U disk.
If the installation fails, restart the device and try again by following the steps (may be useful). Still have questions please add the official QQ group below.