diff --git a/src/app.rs b/src/app.rs
index 3f4b710..b6b807a 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -179,3 +179,5 @@ impl eframe::App for CalculatorApp {
         });
     }
 }
+
+// TODO add tests to ensure expected operation and record how program is expected to work
diff --git a/src/lib.rs b/src/lib.rs
index e72ad16..4ba14a2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,3 +2,5 @@
 
 mod app;
 pub use app::CalculatorApp;
+
+// TODO Add history / current calculation display