Added the method calling HBitcoin's tracker to track blocks.

Breeze.Api/src/Breeze.Api/Startup.cs

-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
-using Microsoft.AspNetCore.Routing;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -36,6 +31,9 @@ namespace Breeze.Api
 
             // add DI classes for controllers. 
             services.AddTransient<ISafeWrapper, SafeWrapper>();
+            services.AddTransient<ITrackerWrapper, TrackerWrapper>();
+
+            
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

Breeze.Api/src/Breeze.Api/Wrappers/ITrackerWrapper.cs

+using NBitcoin;
+
+namespace Breeze.Api.Wrappers
+{
+    public interface ITrackerWrapper
+    {
+        void NotifyAboutBlock(int height, Block block);
+    }
+}

Breeze.Api/src/Breeze.Api/Wrappers/TrackerWrapper.cs

+using NBitcoin;
+using HBitcoin.FullBlockSpv;
+using HBitcoin.Models;
+
+namespace Breeze.Api.Wrappers
+{
+    public class TrackerWrapper : ITrackerWrapper
+    {
+        private readonly Tracker tracker;
+
+        public TrackerWrapper(Network network)
+        {
+            this.tracker = new Tracker(network);              
+        }
+        
+        public void NotifyAboutBlock(int height, Block block)
+        {
+            this.tracker.AddOrReplaceBlock(new Height(height), block);           
+        }
+    }
+}