It is now very easy to install eWeLink on an
Android tablet without a telephone
number. Just get the latest version (22.214.171.124, 2016-11-30) from
Google's Play Store. While it is described as "designed
for phones", it will download to a tablet and an activation code will be sent to
an email address without ever providing a telephone number.
Unfortunately, I could not install this new version on an older tablet
with Android 4.0.4. But I still had
Installing eWeLink on an Android
Tablet). Once I installed that version on the older tablet, it did upgrade to
version 126.96.36.199 and it does work for the most part. The appearance of the
Loop Timer makes it difficult to use, and I have not tested Scenes.
If you don't happen to have the version 2.2.5 application package (and you won't
get the 188.8.131.52 version following my previous post since the
Play Store has the latest version since the 8th of
December), you can install the somewhat different
(available here: http://www.raspberrypiwiki.com/download/E-WeLink-2.1.13.apk). An email
address, without phone number, will get you an activation code. The GUIi is
slightly different, the app looks like it can handle different types of devices,
and I could not get it to "update" to version 184.108.40.206. Still, it if you are
impatient to test your Sonoff, and you can't borrow or
beg an Android phone and your tablet is too old to
obtain version 220.127.116.11, then it is worth a try.
When I tested E-WeLink version 2.1.13, I created a new account (different email, new password). I tried to attach a Sonoff that I had in my original account. The application refused, saying the device belonged to someone else. I found that comforting.