We are getting ready to take our Oliver ("Olivia" #111 and tow "Ruby") on the road again. Last week while gone on a short trip our household freezer stopped working and we came home to water on the floor and food thawing. I am trying to find a themometer I can monitor with my phone while we are gone again. Does anyone have a suggestion for a system that is not very expensive and can be read through an iphone app? Thanks Linda