Review on Wireless RV/Dog Temperature & Humidity Sensor with 4G Verizon Cellular, 24/7 Email/SMS Alerts, No WiFi Needed | iOS/Android Compatible by Joe Fulce

I bought this system based on other good reviews. I planned to travel from Seattle to California, Nevada and Montana. Even though there was electricity where I lived in case something happened, I definitely didn't want my RV to overheat. I read Revain's Q&A and they listed a $120 annual fee, so I bought the device. However, you can choose between $20/month or $180/year per app. So I decided to buy a month later. However, you cannot buy a month, they force you to make monthly payments from your credit card or PayPal. So I did. When I decided to cancel it as I will not be traveling for the next 4 months, I received a $5 cancellation fee. I'm not saying I won't be using it again, but I think all fees and options should be spelled out clearly. And the fee structure and subscription amounts should be in the product description on Revain. Incidentally, Nimble discounts the device if you buy it from their website (instead of Revain), but the package is slightly different. Take a look around and decide what's best for you.