Is there a site / service / cloud that I can create an account, register key / value to use in my Android application via http, returning a json?

I need the following:

1. 
   

   A site where I can create an account and add key/value, something like: "my car" -> "Vectra GL".

   
   


2. 
   

   When I send via web service request the key "my car", it should return a json containing "Vectra GL".

   
   

The purpose of this is that I do not have to maintain a server to return me this json. I want to know if there is already a site / service / cloud that I create an account and register keys / values to be returned when I order via service. A kind of cloud service that already do this.

It can be free or paid. I need something even simple. I want to use this in my Android application, but as it is something generic, some web developer also may have knowledge of something to help me.

Thanks in advance!