Creating very simple apps for android OS is quite simple now using google lab app inventor
I reckon having a clear understanding of OOP will help, but in theory is pretty much like playing with a Lego set.
Warning: file_get_contents(https://www.googleapis.com/plus/v1/people/102759132622433661606/activities/public?maxResults=5&key=AIzaSyCPtQ1XMWetDkVw5XuzNnVXpf8ezDtH9So): failed to open stream: HTTP request failed! HTTP/1.0 403 Forbidden
in /home/trapecis/public_html/wordpress/wp-content/plugins/google-plus-activity/googlePlusActivity.php on line 121