I looked for a tempered glass screen protector for the Jolla, too bad it doesn't exist.

So the hunt begun for a universal one.

And I found the best one that fits in perfectly:

HTC One M7

This one literally just fits in exactly! So you need to align it EXACTLY on the sides. (which is only good!)

You can get those Tempered screenprotectors for like $1.50 on ebay.
http://www.ebay.com/itm/252094476653
(this one is even $1.23 with free shipping)

I took some photos with the glass on it.
You can see the upper and lower line of the glass, so you know where it stars and ends (it's just about the right size)

Oh and for those who wants to know what tempered glass screen protector does vs normal screen protectors:
https://www.youtube.com/watch?v=QFwt5-TUJoM