1. A method of determining cacheability of content received for a client on a mobile device, the method, comprising: tracking requests generated by the client at the mobile device to detect periodicity of the requests generated by the client; tracking responses received for requests generated by the client to detect repeatability in content of the responses; determining whether the content received for the client is cacheable on the mobile device based on one or more of the periodicity in the requests and the repeatability in the content of the responses; wherein, a host which sends the responses is monitored at a rate to verify relevance or validity of the cache entry for the requests; wherein, the rate at which the host is monitored is determined only from the requests generated in the background by the client rather than requests generated from user interaction with the client.