some comments

src/main/java/de/codecentric/boot/admin/SpringBootAdmin.java

@@ -12,6 +12,12 @@ import de.codecentric.boot.admin.config.WebappConfig;
 @Import(WebappConfig.class)
 public class SpringBootAdmin {
 
+	/**
+	 * Starting point for application to boot.
+	 * 
+	 * @param args
+	 *            Passed arguments.
+	 */
 	public static void main(String[] args) {
 		SpringApplication.run(SpringBootAdmin.class, args);
 	}

src/main/java/de/codecentric/boot/admin/config/WebappConfig.java

@@ -14,16 +14,25 @@ import de.codecentric.boot.admin.service.ApplicationRegistry;
 @Configuration
 public class WebappConfig extends WebMvcConfigurerAdapter {
 
+	/**
+	 * Add JSON MessageConverter to send JSON objects to web clients.
+	 */
 	@Override
 	public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
 		converters.add(new MappingJackson2HttpMessageConverter());
 	}
 
+	/**
+	 * Controller with REST-API for spring-boot applications to register itself.
+	 */
 	@Bean
 	public RegistryController registryController() {
 		return new RegistryController();
 	}
 
+	/**
+	 * Registry for all registered application.
+	 */
 	@Bean
 	public ApplicationRegistry applicationRegistry() {
 		return new ApplicationRegistry();

src/main/java/de/codecentric/boot/admin/controller/RegistryController.java

@@ -26,6 +26,13 @@ public class RegistryController {
 	@Autowired
 	private ApplicationRegistry registry;
 
+	/**
+	 * Register an application within this admin application.
+	 * 
+	 * @param app
+	 *            The application infos.
+	 * @return The registered application.
+	 */
 	@RequestMapping(value = "/api/applications", method = RequestMethod.POST)
 	@ResponseBody
 	public Application register(@RequestBody Application app) {
@@ -33,6 +40,13 @@ public class RegistryController {
 		return registry.register(app);
 	}
 
+	/**
+	 * Get a single application out of the registry.
+	 * 
+	 * @param id
+	 *            The application identifier.
+	 * @return The registered application.
+	 */
 	@RequestMapping(value = "/api/application/{id}", method = RequestMethod.GET)
 	@ResponseBody
 	public Application get(@PathVariable String id) {
@@ -40,6 +54,11 @@ public class RegistryController {
 		return registry.getApplication(id);
 	}
 
+	/**
+	 * List all registered applications.
+	 * 
+	 * @return List.
+	 */
 	@RequestMapping(value = "/api/applications", method = RequestMethod.GET)
 	@ResponseBody
 	public List<Application> applications() {

src/main/java/de/codecentric/boot/admin/service/ApplicationRegistry.java

@@ -11,7 +11,8 @@ import org.springframework.stereotype.Service;
 import de.codecentric.boot.admin.model.Application;
 
 /**
- * Registry for all applications that should be managed/administrated by the spring-boot-admin application.
+ * Registry for all applications that should be managed/administrated by the spring-boot-admin application. This
+ * registry is just "in-memory", so that after a restart all applications have to be registered again.
  */
 @Service
 public class ApplicationRegistry {