How to set a tethered Wi-Fi connection (tethered to another phone via Android personal hotspot) as "metered" connection I have a number of apps set to "Download on Wi-Fi Only" on Android. But the moment I tether, the phone considers itself on Wi-Fi, even if the upstream device is a metered 3G/LTE connection.

Under Windows 10, I can declare a given Wi-Fi connection to be "Metered", and thus save data usage.  Is there an equivalent on Android?  Setting the tethered phone to "Data saver" is a partial solution only.
There is a rather hidden feature, that will let you achieve this:

This option is found under Settings > Data usage (Wireless and Networks). 


Tap on the three dots in the top right corner, and press "Mobile Hotspots." (In android 4.3) In later versions of android   the similar option is "Network restrictions" > Metered connections




Next you'll see  a list of saved wireless networks, and you can check the ones which are mobile hotspots.



Edit

I have included the screenshots for Android 7, since interface and options are different from Android 4.3 above:



Such that the options are found under Settings > Data usage (Wi-Fi) > Network restrictions > Metered connections



In this way Android applies the same data restrictions as it does with "Data connections" so no data hogging. 

Update

Other devices like Huawei have this setting hidden but can be also enable using adb:

After setting up adb, follow this proceedure to set a metered wi-fi network.


  
  In a command prompt or terminal, execute the following command: adb
  shell
  Type the following command into the command prompt or terminal to get a list of all saved WiFi networks: cmd netpolicy list
  wifi-networks
  You’ll be given a list of saved WiFi networks with a true/false boolean value. True = metered &amp; False = non-metered.
  So from here, you can enter the following command in a command prompt or terminal to change the setting: cmd netpolicy set
  metered-network Wireless true
     (In this case the SSID  is “Wireless”) 
  You can always revert the setting to false if you want to switch it back to a non-metered network.
  


Hope this helps