Available RAM Memory in an iOS devices

#import mach\mach.h
#import mach\mach_host.h

 static natural_t get_free_memory(void)  
 {  
   mach_port_t host_port;  
   mach_msg_type_number_t host_size;  
   vm_size_t pagesize;  
   host_port = mach_host_self();  
   host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);  
   host_page_size(host_port, &pagesize);  
   vm_statistics_data_t vm_stat;  
   if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS)  
   {  
     NSLog(@"Failed to fetch vm statistics");  
     return 0;  
   }  
   /* Stats in bytes */  
   natural_t mem_free = vm_stat.free_count * pagesize;  
   return mem_free;  
 }