The reference provided discusses the difficulty of making modifications to smart phone hardware.
Which suggests it would not be impossible for smartphone makers to build self-destruct in from the very start. But real hard for it to be retrofitted.
To be useful, the self-destruct sequence would have to be very easy to trigger. When some thug (government or not) “asks” you to hand over your phone you don’t have much time to fiddle with it before complying.
The obvious problem of marketing a mainstream device with an easily triggered incendiary mode of self-destruct are left as an exercise for the reader. 
I want Siri to announce “This phone will self destruct in five seconds.” Then start singing “Daisy, Daisy”.
If not Daisy, than whatever was that haunting lilting melody at the end of Dr. Strangelove while they were showing all the footage of real nuclear tests, standing in for footage of the Soviet Doomsday Machine going off.
Which some very cursory lazy research seems to suggest was a 1940s rendition of Until we meet again
We’ll meet again
By Vera Lynn (of Pink Floyd fame).
Thank you!
The lyrics I could make out were so generic as to be unsearchable. Turns out “meeting again” is a pretty common idea in song lyrics. Who knew?