If for some reason you wanted to limit the speed of any connection on the smartphone, then this article will help you.
This is autotranslated version of this post.
Bandwidth ruler will help to set the limit of speed connections for all network types on a smartphone.
Despite the outdated interface, the app is surprisingly well done. You can specify limits of speed or bandwidth for a mobile, Wi-Fi or Bluetooth connection. Similarly, you can configure tethering or USB connection.
Bandwidth ruler is a little different for smartphones with root and without. But overall the feature set is identical.