As a Theme designer, I want to be able to test themes in devices I do not have. If I can use Remote Test Lab to easily and securely test any theme I have, it would improve operations.
I just did this the other day. Simply export your APK and transfer it to the device using the Files feature. You can then install the APK using the file manager on the phone.
Trying to install it via the Applications menu did not work for me.