As someone who posts about computers quite a bit, I'm finding it hard to not have a backslant key, but I don't see any place on the keyboard where I can select one?
What keyboard are you using? I cam get one if I go into the symbols pages on swype, and is on page 2 of the symbols on the Samsung keyboard (see the screenshot)
To get there, tap the symbols key (replaced by the abc key in this screenshot) then tap the key that replaced the shift key.