diff --git a/pyotb/apps.py b/pyotb/apps.py
index 9bf67599319b7b1fb1fa215f85f86fe3bd92626c..5cc758a68986f50e2cbd951858e8dc508473b830 100644
--- a/pyotb/apps.py
+++ b/pyotb/apps.py
@@ -83,40 +83,57 @@ class {name}(App):
     def __init__(self, *args, **kwargs):
         super().__init__('{name}', *args, **kwargs)
 """
+
+
+class OTBTFApp(App):
+    """
+    Helper for OTBTF
+    """
+    @staticmethod
+    def set_nb_sources(*args, n_sources=None):
+        """Set the number of sources of TensorflowModelServe. Can be either user-defined or deduced from the args
+
+        :param args: arguments (dict). NB: we don't need kwargs because it cannot contain source#.il
+        :param n_sources: number of sources. Default is None (resolves the number of sources based on the
+                          content of the dict passed in args, where some 'source' str is found)
+        """
+        if n_sources:
+            os.environ['OTB_TF_NSOURCES'] = str(int(n_sources))
+        else:
+            # Retrieving the number of `source#.il` parameters
+            params_dic = {k: v for arg in args if isinstance(arg, dict) for k, v in arg.items()}
+            n_sources = len([k for k in params_dic if 'source' in k and k.endswith('.il')])
+            if n_sources >= 1:
+                os.environ['OTB_TF_NSOURCES'] = str(n_sources)
+
+    def __init__(self, app_name, *args, n_sources=None, **kwargs):
+        """
+        :param args: args
+        :param n_sources: number of sources. Default is None (resolves the number of sources based on the
+                          content of the dict passed in args, where some 'source' str is found)
+        :param kwargs: kwargs
+        """
+        self.set_nb_sources(*args, n_sources=n_sources)
+        super().__init__(app_name, *args, **kwargs)
+
+
 for _app in AVAILABLE_APPLICATIONS:
     # Default behavior for any OTB application
     exec(_code_template.format(name=_app))  # pylint: disable=exec-used
 
-    # Customize the behavior for TensorflowModelServe application. The user doesn't need to set the env variable
+    # Customize the behavior for some OTBTF applications. The user doesn't need to set the env variable
     # `OTB_TF_NSOURCES`, it is handled in pyotb
     if _app == 'TensorflowModelServe':
-        class TensorflowModelServe(App):
-            """
-            Helper for OTBTF
-            """
-            @staticmethod
-            def set_nb_sources(*args, n_sources=None):
-                """
-                Set the number of sources of TensorflowModelServe. Can be either user-defined or deduced from the args
-                :param args: arguments
-                :param n_sources: number of sources. Default is None (resolves the number of sources based on the
-                content of the dict passed in args, where some 'source' str is found)
-                """
-                if n_sources:
-                    os.environ['OTB_TF_NSOURCES'] = str(int(n_sources))
-                else:
-                    # Retrieving the number of `source#.il` parameters
-                    params_dic = {k: v for arg in args if isinstance(arg, dict) for k, v in arg.items()}
-                    n_sources = len([k for k in params_dic if k.startswith('source') and k.endswith('.il')])
-                    if n_sources >= 1:
-                        os.environ['OTB_TF_NSOURCES'] = str(n_sources)
+        class TensorflowModelServe(OTBTFApp):
+            def __init__(self, *args, n_sources=None, **kwargs):
+                super().__init__('TensorflowModelServe', *args, n_sources=n_sources, **kwargs)
+
+    elif _app == 'PatchesExtraction':
+        class PatchesExtraction(OTBTFApp):
+            def __init__(self, *args, n_sources=None, **kwargs):
+                super().__init__('PatchesExtraction', *args, n_sources=n_sources, **kwargs)
 
+    elif _app == 'TensorflowModelTrain':
+        class TensorflowModelTrain(OTBTFApp):
             def __init__(self, *args, n_sources=None, **kwargs):
-                """
-                :param args: args
-                :param n_sources: number of sources. Default is None (resolves the number of sources based on the
-                content of the dict passed in args, where some 'source' str is found)
-                :param kwargs: kwargs
-                """
-                self.set_nb_sources(*args, n_sources=n_sources)
-                super().__init__('TensorflowModelServe', *args, **kwargs)
+                super().__init__('TensorflowModelTrain', *args, n_sources=n_sources, **kwargs)