old_contents: bl_info = {
      "name": "Custom file export",
      "description": "Export to custom file format",
      "author": "Aleksi Grön",
      "version": (0, 2),
      "blender": (2, 57, 0),
      "location": "File > Export",
      "category": "Import-Export"
  }
  
  import bpy
  from bpy.props import StringProperty, BoolProperty
  from bpy_extras.io_utils import ExportHelper
  
  class CustomExportFormat(bpy.types.Operator, ExportHelper):
      """My custom format export script"""
      bl_idname = "export_mesh.gtk_mesh"
      bl_label = "Export oag custom"
      
      filename_ext = ".raw"
      filter_glob = StringProperty(default="*.oag", options={'HIDDEN'})
      
      apply_modifiers = BoolProperty(
          name = "Apply Modifiers",
          description = "Apply mesh modifiers before exporting",
          default = True)
  
      def execute(self, context):
          from . import export
          err = export.write(context, self.filepath, self.apply_modifiers)
          if err: print(err)
          
          return {'FINISHED'}
  
  
  def menuItemFunc_Export(self, context):
      self.layout.operator(CustomExportFormat.bl_idname, text="Custom file (*.*)")
  
  def register():
      bpy.utils.register_module(__name__)
      bpy.types.INFO_MT_file_export.append(menuItemFunc_Export)
  
  def unregister():
      bpy.utils.unregister_module(__name__)
      bpy.types.INFO_MT_file_export.remove(menuItemFunc_Export)
  
  if __name__ == "__main__":
      register()
  
new_contents: bl_info = {
      "name": "Custom mesh export",
      "description": "Export mesh to custom file format",
      "author": "Aleksi Grön",
      "version": (0, 2),
      "blender": (2, 57, 0),
      "location": "File > Export",
      "category": "Import-Export"
  }
  
  import bpy
  from bpy.props import StringProperty, BoolProperty
  from bpy_extras.io_utils import ExportHelper
  
  class CustomExportFormat(bpy.types.Operator, ExportHelper):
      """Custom format mesh export script"""
      bl_idname = "export_mesh.gtk_mesh"
      bl_label = "Export custom mesh"
      
      filename_ext = ".mesh"
      filter_glob = StringProperty(default="*.mesh", options={'HIDDEN'})
      
      apply_modifiers = BoolProperty(
          name = "Apply Modifiers",
          description = "Apply mesh modifiers before exporting",
          default = True)
  
      def execute(self, context):
          from . import export
          err = export.write(context, self.filepath, self.apply_modifiers)
          if err: print(err)
          
          return {'FINISHED'}
  
  
  def menuItemFunc_Export(self, context):
      self.layout.operator(CustomExportFormat.bl_idname, text="Custom file (.mesh)")
  
  def register():
      bpy.utils.register_module(__name__)
      bpy.types.INFO_MT_file_export.append(menuItemFunc_Export)
  
  def unregister():
      bpy.utils.unregister_module(__name__)
      bpy.types.INFO_MT_file_export.remove(menuItemFunc_Export)
  
  if __name__ == "__main__":
      register()
  
subject: Fix some texts in export script