diff --git a/androscalpel/src/apk.rs b/androscalpel/src/apk.rs
index 13bc925..11f55d7 100644
--- a/androscalpel/src/apk.rs
+++ b/androscalpel/src/apk.rs
@@ -3072,6 +3072,16 @@ impl Apk {
         Ok(())
     }
 
+    /// List the classes implemented in the application.
+    pub fn list_classes(&self) -> HashSet<IdType> {
+        self.dex_files
+            .values()
+            .map(|dex| dex.classes.keys())
+            .flatten()
+            .cloned()
+            .collect()
+    }
+
     pub fn add_class(&mut self, dex_file: &str, class: Class) -> Result<()> {
         let file: String = dex_file.into();
         let id = class.descriptor.clone();