Add extra features to my WEBSERVICES

Hi I already have an app with some webservices running. Both front-end(android) and back-end(php-webservice) are available. I want to add more features to my app's webservices. Below are the features: App side(front end): ======= Show total no. of users and total number of ads ------------------------------------------ Share Ads option.(after user installs the App it should show the ad) ------------------------------------------ Show number of clicks on the ads ------------------------------------------ Show ad posted and expiry date ------------------------------------------ Auto hide Ad after expiry. User must pay again to activate ------------------------------------------ During search show latest ads on top ------------------------------------------ Display Google ads in bottom on all pages ------------------------------------------ Display my Ads in between Search ads ------------------------------------------ POST RENTAL - post Required Ads SEARCH RENTAL - Show Required Ads ------------------------------------------ AD chat facility - Multiple Users can post/edit/delete comments to the ad shown(under SEARCH RENTAL) ----------------------------------------- During AD posting ask Days [30/60/90] and Rs[100/200/300] <----- Dropdown fields ----------------------------------------- If City = outside India city then Currency = $ Show Paypal payment if City = outside India city. ----------------------------------------- Admin side ======== Show email id also below phone number ----------------------------------------- Show latest Ads on Top. Right now it is reverse. ----------------------------------------- Admin can post his ads in between search page ads. ----------------------------------------- Admin can Delete approved comments also. ----------------------------------------- Please tell me the time and fees need for these features.