I use my phone. I got the information about the French readers from a Dutch Facebook group where people use them without problem so I'm willing to bet Spanish ones work fine too
That's a very useful tip for any questions about another country! Expats tend to have money too, so when they have diabetes they'll buy Libres
For now, I think I'll leave the scavenger hunt to my aunt, as they'll be sightseeing and visiting a lot of towns, so they'll see a lot of pharmacies. And she liked the idea of hunting for them!
I'll give you an update as soon as she finds out of course.