make App easily subclassable

example_apps/MinimalApp/MinimalApp.h

@@ -0,0 +1,51 @@
+#ifndef APP_H
+#define APP_H
+
+#include "pch.hpp"
+#include "utils/Module/Module.h"
+
+namespace Archimedes {
+    
+    class App {
+
+        private:
+            static App* instance;
+
+            bool done = false;
+
+            std::list<Module*> modules;
+            std::list<Module*> toClose;
+            std::list<std::string> toOpen;
+
+            bool load(std::string, std::list<std::string>);
+            void unload(std::list<Module*>::iterator);
+
+            void handleArgs(const int&, char*[]);
+
+            void printHelp();
+
+            std::list<std::string> getBlacklist() {
+                std::list<std::string> l;
+                for(Module* m : modules)
+                    l.push_back(m->getName());
+                return l;
+            }
+
+        public:
+            App(const int&, char*[]);
+            ~App();
+
+            static App& Get() { return *instance; }
+
+            void run();
+
+            void stopModule(std::list<Module*>::iterator);
+
+            void startModule(std::string);
+
+            void end() { done = true; }
+    };
+
+}
+
+#endif