diff --git a/crates/composition/src/builder.rs b/crates/composition/src/builder.rs
index e438b29..88790a2 100644
--- a/crates/composition/src/builder.rs
+++ b/crates/composition/src/builder.rs
@@ -1,5 +1,5 @@
 use crate::Result;
-use crate::system::App;
+use crate::system::SingleWindowShell;
 use layer_shika_adapters::platform::slint_interpreter::{CompilationResult, Compiler};
 use layer_shika_domain::errors::DomainError;
 use layer_shika_domain::prelude::{
@@ -202,7 +202,7 @@ impl LayerShika<HasComponent> {
         self
     }
 
-    pub fn build(self) -> Result<App> {
+    pub fn build(self) -> Result<SingleWindowShell> {
         let component_definition = self
             .state
             .compilation_result
@@ -214,7 +214,7 @@ impl LayerShika<HasComponent> {
                 ),
             })?;
 
-        App::new(
+        SingleWindowShell::new(
             component_definition,
             Some(self.state.compilation_result),
             self.config,
diff --git a/crates/composition/src/lib.rs b/crates/composition/src/lib.rs
index 1357861..4308ffb 100644
--- a/crates/composition/src/lib.rs
+++ b/crates/composition/src/lib.rs
@@ -27,7 +27,7 @@ pub use layer_shika_domain::value_objects::popup_request::{
     PopupHandle, PopupPlacement, PopupRequest, PopupSize,
 };
 pub use popup_builder::PopupBuilder;
-pub use system::{App, EventContext, EventLoopHandle, ShellControl};
+pub use system::{EventContext, EventLoopHandle, ShellControl, SingleWindowShell};
 
 pub use shell::{
     LayerSurfaceHandle, Shell, ShellEventContext, ShellEventLoopHandle, ShellWindowConfigHandler,
@@ -57,10 +57,10 @@ pub enum Error {
 
 pub mod prelude {
     pub use crate::{
-        AnchorEdges, AnchorStrategy, App, EventContext, EventLoopHandle, KeyboardInteractivity,
-        Layer, LayerShika, OutputGeometry, OutputHandle, OutputInfo, OutputPolicy, OutputRegistry,
+        AnchorEdges, AnchorStrategy, EventContext, EventLoopHandle, KeyboardInteractivity, Layer,
+        LayerShika, OutputGeometry, OutputHandle, OutputInfo, OutputPolicy, OutputRegistry,
         PopupBuilder, PopupHandle, PopupPlacement, PopupPositioningMode, PopupRequest, PopupSize,
-        PopupWindow, Result, ShellControl,
+        PopupWindow, Result, ShellControl, SingleWindowShell,
     };
 
     pub use crate::{
diff --git a/crates/composition/src/popup_builder.rs b/crates/composition/src/popup_builder.rs
index 361f74f..97babe2 100644
--- a/crates/composition/src/popup_builder.rs
+++ b/crates/composition/src/popup_builder.rs
@@ -1,12 +1,12 @@
 use crate::Result;
-use crate::system::App;
+use crate::system::SingleWindowShell;
 use layer_shika_adapters::platform::slint_interpreter::Value;
 use layer_shika_domain::prelude::AnchorStrategy;
 use layer_shika_domain::value_objects::popup_positioning_mode::PopupPositioningMode;
 use layer_shika_domain::value_objects::popup_request::{PopupPlacement, PopupRequest, PopupSize};
 
 pub struct PopupBuilder<'a> {
-    app: &'a App,
+    shell: &'a SingleWindowShell,
     component: String,
     reference: PopupPlacement,
     anchor: PopupPositioningMode,
@@ -17,9 +17,9 @@ pub struct PopupBuilder<'a> {
 }
 
 impl<'a> PopupBuilder<'a> {
-    pub(crate) fn new(app: &'a App, component: String) -> Self {
+    pub(crate) fn new(shell: &'a SingleWindowShell, component: String) -> Self {
         Self {
-            app,
+            shell,
             component,
             reference: PopupPlacement::AtCursor,
             anchor: PopupPositioningMode::TopLeft,
@@ -146,9 +146,9 @@ impl<'a> PopupBuilder<'a> {
 
     pub fn bind(self, trigger_callback: &str) -> Result<()> {
         let request = self.build_request();
-        let control = self.app.control();
+        let control = self.shell.control();
 
-        self.app.with_all_component_instances(|instance| {
+        self.shell.with_all_component_instances(|instance| {
             let request_clone = request.clone();
             let control_clone = control.clone();
 
@@ -171,10 +171,10 @@ impl<'a> PopupBuilder<'a> {
 
     pub fn toggle(self, trigger_callback: &str) -> Result<()> {
         let request = self.build_request();
-        let control = self.app.control();
+        let control = self.shell.control();
         let component_name = request.component.clone();
 
-        self.app.with_all_component_instances(|instance| {
+        self.shell.with_all_component_instances(|instance| {
             let request_clone = request.clone();
             let control_clone = control.clone();
             let component_clone = component_name.clone();
@@ -203,9 +203,9 @@ impl<'a> PopupBuilder<'a> {
         let grab = self.grab;
         let close_callback = self.close_callback.clone();
         let resize_callback = self.resize_callback.clone();
-        let control = self.app.control();
+        let control = self.shell.control();
 
-        self.app.with_all_component_instances(|instance| {
+        self.shell.with_all_component_instances(|instance| {
             let component_clone = component_name.clone();
             let control_clone = control.clone();
             let close_cb = close_callback.clone();
diff --git a/crates/composition/src/system.rs b/crates/composition/src/system.rs
index 9932fcc..28e4e12 100644
--- a/crates/composition/src/system.rs
+++ b/crates/composition/src/system.rs
@@ -308,12 +308,18 @@ impl EventContext<'_> {
             })
         })?;
 
-        log::debug!("Got compilation result, looking for component '{}'", req.component);
+        log::debug!(
+            "Got compilation result, looking for component '{}'",
+            req.component
+        );
 
         let definition = compilation_result
             .component(&req.component)
             .ok_or_else(|| {
-                log::error!("Component '{}' not found in compilation result", req.component);
+                log::error!(
+                    "Component '{}' not found in compilation result",
+                    req.component
+                );
                 Error::Domain(DomainError::Configuration {
                     message: format!(
                         "{} component not found in compilation result",
@@ -637,12 +643,12 @@ impl EventContext<'_> {
     }
 }
 
-pub struct App {
+pub struct SingleWindowShell {
     inner: Rc<RefCell<WindowingSystemFacade>>,
     popup_command_sender: channel::Sender<PopupCommand>,
 }
 
-impl App {
+impl SingleWindowShell {
     pub(crate) fn new(
         component_definition: ComponentDefinition,
         compilation_result: Option<Rc<CompilationResult>>,
@@ -659,14 +665,14 @@ impl App {
 
         let (sender, receiver) = channel::channel();
 
-        let system = Self {
+        let shell = Self {
             inner: Rc::clone(&inner_rc),
             popup_command_sender: sender,
         };
 
-        system.setup_popup_command_handler(receiver)?;
+        shell.setup_popup_command_handler(receiver)?;
 
-        Ok(system)
+        Ok(shell)
     }
 
     fn setup_popup_command_handler(&self, receiver: channel::Channel<PopupCommand>) -> Result<()> {
diff --git a/src/lib.rs b/src/lib.rs
index 28ab3ca..a8a50c9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -63,10 +63,10 @@
 pub mod prelude;
 
 pub use layer_shika_composition::{
-    AnchorEdges, AnchorStrategy, App, Error, EventContext, EventLoopHandle, KeyboardInteractivity,
+    AnchorEdges, AnchorStrategy, Error, EventContext, EventLoopHandle, KeyboardInteractivity,
     Layer, LayerShika, OutputGeometry, OutputHandle, OutputInfo, OutputPolicy, OutputRegistry,
     PopupHandle, PopupPlacement, PopupPositioningMode, PopupRequest, PopupSize, PopupWindow,
-    Result, ShellControl,
+    Result, ShellControl, SingleWindowShell,
 };
 
 pub use layer_shika_composition::{
diff --git a/src/prelude.rs b/src/prelude.rs
index 6fa7b77..4850c1a 100644
--- a/src/prelude.rs
+++ b/src/prelude.rs
@@ -9,7 +9,8 @@
 #![allow(clippy::pub_use)]
 
 pub use crate::{
-    App, Error, EventContext, EventLoopHandle, LayerShika, PopupWindow, Result, ShellControl,
+    Error, EventContext, EventLoopHandle, LayerShika, PopupWindow, Result, ShellControl,
+    SingleWindowShell,
 };
 
 pub use crate::{