How to implement cache system in php for json api

I have a few custom social buttons on my website for whom
I get the share number/followers number using json from API.
I have tried to
implement a cache system to reduce the load time and eliminate de risk of being
'red-flagged' for over-using the APIs. However, I had no success in this area, basically
because I don't quite understand the integration steps.
I hope someone could
help me integrate a cache system.

Here are the
php codes for Twitter, Google Plus and
Instagram:

            ob_start();
 $twittershare =
            'http://cdn.api.twitter.com/1/urls/count.json?url='.$product["href"]
            .'';

 $ch = curl_init();
 curl_setopt($ch, CURLOPT_URL,
            $twittershare);
 curl_setopt($ch, CURLOPT_HEADER, 0);
 $jsonstring =
            curl_exec($ch);
 curl_close($ch);
 $bufferstr =
            ob_get_contents();
 ob_end_clean();
 $json =
            json_decode($bufferstr);

 echo
            $json->count;

• Google
  Plus

            $url = ''.$product["href"] .'';

 $ch = curl_init();

            curl_setopt($ch, CURLOPT_URL,
            "https://clients6.google.com/rpc?key=xxxxxxxxxx");
 curl_setopt($ch,
            CURLOPT_POST, 1);
 curl_setopt($ch, CURLOPT_POSTFIELDS,
            '[{"method":"pos.plusones.get","id":"p","params":{"nolog":true,"id":"' . $url .
            '","source":"widget","userId":"@viewer","groupId":"@self"},"jsonrpc":"2.0","key":"p","apiVersion":"v1"}]');

            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
 curl_setopt($ch,
            CURLOPT_HTTPHEADER, array('Content-type: application/json'));

            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
 $curl_results =
            curl_exec($ch);
 curl_close($ch);
 $json =
            json_decode($curl_results, true);
 $count =
            intval($json[0]['result']['metadata']['globalCounts']['count']);
 $data =
            array();
 $data['plus_count'] = (string) $count;
 $data['url'] =
            $url;
 echo
            $data['plus_count'];

• Instagram
  (fetching followers
  number)

            ob_start();
 $insta =
            'https://api.instagram.com/v1/users/00000000?access_token={token}';


            $ch = curl_init();
 curl_setopt($ch, CURLOPT_URL, $insta);

            curl_setopt($ch, CURLOPT_HEADER, 0);
 $jsonstring = curl_exec($ch);

            curl_close($ch);
 $bufferstr = ob_get_contents();

            ob_end_clean();
 $json = json_decode($bufferstr);

 echo
            $json->data->counts->followed_by;

Hope
you guys can guide me step by step as to how to implement a cache system for the code
snippets above.