Won't recognise my login details.

Doesn't work. Clicking "options" refuses to open inside Firefox settings and redirects to some external site. Useless.

Uses high CPU Usage when not viewing Amazon pages.

Not installed on Firefox for Android

Funziona benissimo, mostra i prezzi passati e puoi anche decidere cosa vuoi che il grafico mostri (usato, amazon warehouse)

va de maravilla para saber la evolución histórica de los precios en Amazon

Doesn't work for Amazon Australia despite requiring that permission