What IoT services are available for storing/sending/publishing (and opposite operations) generic small amount of data in the cloud?
I am looking, for example, for a service where a device could store a value in the cloud. And some other entity (another device, a website with some JS code, a web server, a mobile app) could retrieve this value.
It could be some kind of asynchronous communication, for example for storing and retrieving something as small as a key&value pair, <255bytes, an integer, a string, at most a small JSON object. The service could offer a REST API (so it could be accessed by a large variety of languages) with some token to authenticate and the key & value to store.
A detailed example of a use case is:
There is a temperature sensor at home, and I want it to store the value in the cloud(somewhere out of home). In such way, I could access it, regardless of my home connection is down or not. Morevoer, this would avoid keeping and maintaining a dedicated server + portForwarding + DynamicDNS.
So far I have not been able to find something like this, but occasionally, I have found some examples of what I mean to describe:
What other similar (free/open) alternatives are there?