diff --git a/src/ultraleap.cpp b/src/ultraleap.cpp
index 6e004ff..ee47d98 100644
--- a/src/ultraleap.cpp
+++ b/src/ultraleap.cpp
@@ -495,7 +495,7 @@ void UltraleapHandTracking::serviceMessageLoop() {
     is_running = false;
 }
 
-UltraleapTypes::TrackingMode UltraleapHandTracking::get_tracking_mode() {
+UltraleapTypes::TrackingMode UltraleapHandTracking::get_tracking_mode() const {
     if (primary_device == NULL) {
         return UltraleapTypes::TrackingMode::Desktop;
     }
@@ -556,11 +556,11 @@ void UltraleapHandTracking::set_policy(UltraleapTypes::PolicyFlag flag, bool val
     LeapSetPolicyFlags(connectionHandle, set_flags, clear_flags);
 }
 
-bool UltraleapHandTracking::get_images_policy() {
+bool UltraleapHandTracking::get_images_policy() const {
     return get_policy(UltraleapTypes::PolicyFlag::Images);
 }
 
-bool UltraleapHandTracking::get_policy(UltraleapTypes::PolicyFlag flag) {
+bool UltraleapHandTracking::get_policy(UltraleapTypes::PolicyFlag flag) const {
     return UltraleapTypes::read_policy_flag(policy_flags, flag);
 }
 
@@ -819,11 +819,11 @@ void UltraleapHandTracking::set_primary_device(Ref<UltraleapDevice> device) {
     LeapSetPrimaryDevice(connectionHandle, device->device, false);
 }
 
-Ref<UltraleapDevice> UltraleapHandTracking::get_primary_device() {
+Ref<UltraleapDevice> UltraleapHandTracking::get_primary_device() const {
     return primary_device;
 }
 
-Ref<UltraleapFrame> UltraleapHandTracking::get_last_frame() {
+Ref<UltraleapFrame> UltraleapHandTracking::get_last_frame() const {
     if (primary_device == NULL) {
         return NULL;
     }
@@ -831,7 +831,7 @@ Ref<UltraleapFrame> UltraleapHandTracking::get_last_frame() {
     return primary_device->get_last_frame();
 }
 
-Ref<UltraleapImage> UltraleapHandTracking::get_left_image() {
+Ref<UltraleapImage> UltraleapHandTracking::get_left_image() const {
     if (primary_device == NULL) {
         return NULL;
     }
@@ -839,7 +839,7 @@ Ref<UltraleapImage> UltraleapHandTracking::get_left_image() {
     return primary_device->get_left_image();
 }
 
-Ref<UltraleapImage> UltraleapHandTracking::get_right_image() {
+Ref<UltraleapImage> UltraleapHandTracking::get_right_image() const {
     if (primary_device == NULL) {
         return NULL;
     }
diff --git a/src/ultraleap.h b/src/ultraleap.h
index aec937c..931711b 100644
--- a/src/ultraleap.h
+++ b/src/ultraleap.h
@@ -35,11 +35,6 @@ public:
 
     UltraleapTypes::TrackingMode default_tracking_mode = UltraleapTypes::TrackingMode::Desktop;
 
-    bool interpolate = true;
-
-    bool get_interpolate();
-    void set_interpolate(bool value);
-
     Ref<UltraleapDeviceList> devices;
 
     String service_ip = String("127.0.0.1");
@@ -48,30 +43,30 @@ public:
     bool autostart = true;
     bool enable_images = true;
 
-    UltraleapTypes::TrackingMode get_tracking_mode();
+    UltraleapTypes::TrackingMode get_tracking_mode() const;
     void set_tracking_mode(UltraleapTypes::TrackingMode value);
 
-    Ref<UltraleapFrame> get_last_frame();
-    Ref<UltraleapImage> get_left_image();
-    Ref<UltraleapImage> get_right_image();
+    Ref<UltraleapFrame> get_last_frame() const;
+    Ref<UltraleapImage> get_left_image() const;
+    Ref<UltraleapImage> get_right_image() const;
 
-    Array get_devices() { return devices->devices; }
+    Array get_devices() const { return devices->devices; }
     void set_devices(Array value) { devices->devices = value; }
 
-    String get_service_ip() { return service_ip; }
+    String get_service_ip() const { return service_ip; }
     void set_service_ip(String value) { service_ip = value; }
 
-    int get_service_port() { return service_port; }
+    int get_service_port() const { return service_port; }
     void set_service_port(int value) { service_port = value; }
 
-    bool get_autostart() { return autostart; }
+    bool get_autostart() const { return autostart; }
     void set_autostart(bool value) { autostart = value; }
 
-    bool get_enable_images() { return enable_images; }
+    bool get_enable_images() const { return enable_images; }
     void set_enable_images(bool value) { enable_images = value; }
 
-    bool is_connected() { return connected; }
-    bool is_started() { return started; }
+    bool is_connected() const { return connected; }
+    bool is_started() const { return started; }
 
     // Policy setters
     void set_images_policy(bool value);
@@ -81,11 +76,11 @@ public:
 
     // Policy getters
     // Only reimplementing the things we know do something
-    bool get_images_policy();
+    bool get_images_policy() const;
 
     // Set and get primary device
     void set_primary_device(Ref<UltraleapDevice> device);
-    Ref<UltraleapDevice> get_primary_device();
+    Ref<UltraleapDevice> get_primary_device() const;
 
     void set_pause(bool value);
 
@@ -122,7 +117,7 @@ private:
     void handle_device_status_change_event(const LEAP_DEVICE_STATUS_CHANGE_EVENT* event, uint32_t device_id);
 
     void set_policy(UltraleapTypes::PolicyFlag flag, bool value);
-    bool get_policy(UltraleapTypes::PolicyFlag flag);
+    bool get_policy(UltraleapTypes::PolicyFlag flag) const;
 
     String generate_connection_payload();