diff --git a/res/xml/settings.xml b/res/xml/settings.xml
index 653a3b0..f5a7eed 100644
--- a/res/xml/settings.xml
+++ b/res/xml/settings.xml
@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto">
   <PreferenceCategory android:title="@string/pref_category_layout">
-    <juloo.keyboard2.LayoutsPreference/>
+    <juloo.keyboard2.prefs.LayoutsPreference/>
     <PreferenceScreen android:title="@string/pref_extra_keys_title">
       <PreferenceCategory android:title="@string/pref_extra_keys_custom">
-        <juloo.keyboard2.CustomExtraKeysPreference/>
+        <juloo.keyboard2.prefs.CustomExtraKeysPreference/>
       </PreferenceCategory>
-      <juloo.keyboard2.ExtraKeysPreference android:title="@string/pref_extra_keys_internal"/>
+      <juloo.keyboard2.prefs.ExtraKeysPreference android:title="@string/pref_extra_keys_internal"/>
     </PreferenceScreen>
     <CheckBoxPreference android:key="number_row" android:title="@string/pref_number_row_title" android:summary="@string/pref_number_row_summary" android:defaultValue="false"/>
     <ListPreference android:key="show_numpad" android:title="@string/pref_show_numpad_title" android:summary="%s" android:defaultValue="1" android:entries="@array/pref_show_numpad_entries" android:entryValues="@array/pref_show_numpad_values"/>
@@ -14,37 +14,37 @@
   </PreferenceCategory>
   <PreferenceCategory android:title="@string/pref_category_typing">
     <ListPreference android:key="swipe_dist" android:title="@string/pref_swipe_dist_title" android:summary="@string/pref_swipe_dist_summary" android:defaultValue="15" android:entries="@array/pref_swipe_dist_entries" android:entryValues="@array/pref_swipe_dist_values"/>
-    <juloo.common.IntSlideBarPreference android:key="longpress_timeout" android:title="@string/pref_long_timeout_title" android:summary="%sms" android:defaultValue="600" min="50" max="2000"/>
-    <juloo.common.IntSlideBarPreference android:key="longpress_interval" android:title="@string/pref_long_interval_title" android:summary="%sms" android:defaultValue="25" min="5" max="100"/>
+    <juloo.keyboard2.prefs.IntSlideBarPreference android:key="longpress_timeout" android:title="@string/pref_long_timeout_title" android:summary="%sms" android:defaultValue="600" min="50" max="2000"/>
+    <juloo.keyboard2.prefs.IntSlideBarPreference android:key="longpress_interval" android:title="@string/pref_long_interval_title" android:summary="%sms" android:defaultValue="25" min="5" max="100"/>
     <CheckBoxPreference android:key="lock_double_tap" android:title="@string/pref_lock_double_tap_title" android:summary="@string/pref_lock_double_tap_summary" android:defaultValue="false"/>
   </PreferenceCategory>
   <PreferenceCategory android:title="@string/pref_category_behavior">
     <CheckBoxPreference android:key="autocapitalisation" android:title="@string/pref_autocapitalisation_title" android:summary="@string/pref_autocapitalisation_summary" android:defaultValue="true"/>
     <CheckBoxPreference android:key="switch_input_immediate" android:title="@string/pref_switch_input_immediate_title" android:summary="@string/pref_switch_input_immediate_summary" android:defaultValue="false"/>
     <CheckBoxPreference android:key="vibrate_custom" android:title="@string/pref_vibrate_custom" android:defaultValue="false"/>
-    <juloo.common.IntSlideBarPreference android:dependency="vibrate_custom" android:key="vibrate_duration" android:title="@string/pref_vibrate_duration_title" android:summary="%sms" android:defaultValue="20" min="0" max="100"/>
+    <juloo.keyboard2.prefs.IntSlideBarPreference android:dependency="vibrate_custom" android:key="vibrate_duration" android:title="@string/pref_vibrate_duration_title" android:summary="%sms" android:defaultValue="20" min="0" max="100"/>
     <CheckBoxPreference android:key="pin_entry_enabled" android:title="@string/pref_pin_entry_enabled_title" android:summary="@string/pref_pin_entry_enabled_summary" android:defaultValue="true"/>
   </PreferenceCategory>
   <PreferenceCategory android:title="@string/pref_category_style">
     <ListPreference android:key="theme" android:title="@string/pref_theme" android:summary="%s" android:defaultValue="system" android:entries="@array/pref_theme_entries" android:entryValues="@array/pref_theme_values"/>
-    <juloo.common.IntSlideBarPreference android:key="label_brightness" android:title="@string/pref_label_brightness" android:summary="%s%%" android:defaultValue="100" min="50" max="100"/>
-    <juloo.common.IntSlideBarPreference android:key="keyboard_opacity" android:title="@string/pref_keyboard_opacity" android:summary="%s%%" android:defaultValue="100" min="0" max="100"/>
-    <juloo.common.IntSlideBarPreference android:key="key_opacity" android:title="@string/pref_key_opacity" android:summary="%s%%" android:defaultValue="100" min="0" max="100"/>
-    <juloo.common.IntSlideBarPreference android:key="key_activated_opacity" android:title="@string/pref_key_activated_opacity" android:summary="%s%%" android:defaultValue="100" min="0" max="100"/>
+    <juloo.keyboard2.prefs.IntSlideBarPreference android:key="label_brightness" android:title="@string/pref_label_brightness" android:summary="%s%%" android:defaultValue="100" min="50" max="100"/>
+    <juloo.keyboard2.prefs.IntSlideBarPreference android:key="keyboard_opacity" android:title="@string/pref_keyboard_opacity" android:summary="%s%%" android:defaultValue="100" min="0" max="100"/>
+    <juloo.keyboard2.prefs.IntSlideBarPreference android:key="key_opacity" android:title="@string/pref_key_opacity" android:summary="%s%%" android:defaultValue="100" min="0" max="100"/>
+    <juloo.keyboard2.prefs.IntSlideBarPreference android:key="key_activated_opacity" android:title="@string/pref_key_activated_opacity" android:summary="%s%%" android:defaultValue="100" min="0" max="100"/>
     <PreferenceScreen android:title="@string/pref_margin_bottom_title">
-      <juloo.common.IntSlideBarPreference android:key="margin_bottom_portrait" android:title="@string/pref_portrait" android:summary="%sdp" android:defaultValue="7" min="0" max="100"/>
-      <juloo.common.IntSlideBarPreference android:key="margin_bottom_landscape" android:title="@string/pref_landscape" android:summary="%sdp" android:defaultValue="3" min="0" max="100"/>
+      <juloo.keyboard2.prefs.IntSlideBarPreference android:key="margin_bottom_portrait" android:title="@string/pref_portrait" android:summary="%sdp" android:defaultValue="7" min="0" max="100"/>
+      <juloo.keyboard2.prefs.IntSlideBarPreference android:key="margin_bottom_landscape" android:title="@string/pref_landscape" android:summary="%sdp" android:defaultValue="3" min="0" max="100"/>
     </PreferenceScreen>
     <PreferenceScreen android:title="@string/pref_keyboard_height_title">
-      <juloo.common.IntSlideBarPreference android:key="keyboard_height" android:title="@string/pref_portrait" android:summary="%s%%" android:defaultValue="35" min="10" max="50"/>
-      <juloo.common.IntSlideBarPreference android:key="keyboard_height_landscape" android:title="@string/pref_landscape" android:summary="%s%%" android:defaultValue="50" min="20" max="65"/>
+      <juloo.keyboard2.prefs.IntSlideBarPreference android:key="keyboard_height" android:title="@string/pref_portrait" android:summary="%s%%" android:defaultValue="35" min="10" max="50"/>
+      <juloo.keyboard2.prefs.IntSlideBarPreference android:key="keyboard_height_landscape" android:title="@string/pref_landscape" android:summary="%s%%" android:defaultValue="50" min="20" max="65"/>
     </PreferenceScreen>
     <PreferenceScreen android:title="@string/pref_horizontal_margin_title">
-      <juloo.common.IntSlideBarPreference android:key="horizontal_margin_portrait" android:title="@string/pref_portrait" android:summary="%sdp" android:defaultValue="3" min="0" max="30"/>
-      <juloo.common.IntSlideBarPreference android:key="horizontal_margin_landscape" android:title="@string/pref_landscape" android:summary="%sdp" android:defaultValue="28" min="0" max="200"/>
+      <juloo.keyboard2.prefs.IntSlideBarPreference android:key="horizontal_margin_portrait" android:title="@string/pref_portrait" android:summary="%sdp" android:defaultValue="3" min="0" max="30"/>
+      <juloo.keyboard2.prefs.IntSlideBarPreference android:key="horizontal_margin_landscape" android:title="@string/pref_landscape" android:summary="%sdp" android:defaultValue="28" min="0" max="200"/>
     </PreferenceScreen>
-    <juloo.common.SlideBarPreference android:key="character_size" android:title="@string/pref_character_size_title" android:summary="@string/pref_character_size_summary" android:defaultValue="1.0" min="0.75" max="1.5"/>
-    <juloo.common.IntSlideBarPreference android:key="key_vertical_space" android:title="@string/pref_key_vertical_space" android:summary="%sdp" android:defaultValue="2" min="0" max="8"/>
-    <juloo.common.IntSlideBarPreference android:key="key_horizontal_space" android:title="@string/pref_key_horizontal_space" android:summary="%sdp" android:defaultValue="2" min="0" max="8"/>
+    <juloo.keyboard2.prefs.SlideBarPreference android:key="character_size" android:title="@string/pref_character_size_title" android:summary="@string/pref_character_size_summary" android:defaultValue="1.0" min="0.75" max="1.5"/>
+    <juloo.keyboard2.prefs.IntSlideBarPreference android:key="key_vertical_space" android:title="@string/pref_key_vertical_space" android:summary="%sdp" android:defaultValue="2" min="0" max="8"/>
+    <juloo.keyboard2.prefs.IntSlideBarPreference android:key="key_horizontal_space" android:title="@string/pref_key_horizontal_space" android:summary="%sdp" android:defaultValue="2" min="0" max="8"/>
   </PreferenceCategory>
 </PreferenceScreen>
diff --git a/srcs/juloo.keyboard2/Autocapitalisation.java b/srcs/juloo.keyboard2/Autocapitalisation.java
index b73f2e3..3baff48 100644
--- a/srcs/juloo.keyboard2/Autocapitalisation.java
+++ b/srcs/juloo.keyboard2/Autocapitalisation.java
@@ -8,7 +8,7 @@ import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputConnection;
 import android.view.KeyEvent;
 
-final class Autocapitalisation
+public final class Autocapitalisation
 {
   boolean _enabled = false;
   boolean _should_enable_shift = false;
diff --git a/srcs/juloo.keyboard2/Config.java b/srcs/juloo.keyboard2/Config.java
index cb68e80..f59bce3 100644
--- a/srcs/juloo.keyboard2/Config.java
+++ b/srcs/juloo.keyboard2/Config.java
@@ -14,8 +14,11 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import juloo.keyboard2.prefs.CustomExtraKeysPreference;
+import juloo.keyboard2.prefs.ExtraKeysPreference;
+import juloo.keyboard2.prefs.LayoutsPreference;
 
-final class Config
+public final class Config
 {
   private final SharedPreferences _prefs;
 
diff --git a/srcs/juloo.keyboard2/ExtraKeys.java b/srcs/juloo.keyboard2/ExtraKeys.java
index ca9e46a..416e507 100644
--- a/srcs/juloo.keyboard2/ExtraKeys.java
+++ b/srcs/juloo.keyboard2/ExtraKeys.java
@@ -9,7 +9,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-class ExtraKeys
+public final class ExtraKeys
 {
   public static final ExtraKeys EMPTY = new ExtraKeys(Collections.EMPTY_LIST);
 
diff --git a/srcs/juloo.keyboard2/KeyEventHandler.java b/srcs/juloo.keyboard2/KeyEventHandler.java
index e903bdb..c79d002 100644
--- a/srcs/juloo.keyboard2/KeyEventHandler.java
+++ b/srcs/juloo.keyboard2/KeyEventHandler.java
@@ -7,7 +7,7 @@ import android.view.inputmethod.ExtractedText;
 import android.view.inputmethod.ExtractedTextRequest;
 import android.view.inputmethod.InputConnection;
 
-class KeyEventHandler implements Config.IKeyEventHandler
+public final class KeyEventHandler implements Config.IKeyEventHandler
 {
   IReceiver _recv;
   Autocapitalisation _autocap;
diff --git a/srcs/juloo.keyboard2/KeyModifier.java b/srcs/juloo.keyboard2/KeyModifier.java
index 984db2e..c0f5beb 100644
--- a/srcs/juloo.keyboard2/KeyModifier.java
+++ b/srcs/juloo.keyboard2/KeyModifier.java
@@ -4,7 +4,7 @@ import android.view.KeyCharacterMap;
 import android.view.KeyEvent;
 import java.util.HashMap;
 
-class KeyModifier
+public final class KeyModifier
 {
   /** Cache key is KeyValue's name */
   private static HashMap<KeyValue, HashMap<Pointers.Modifiers, KeyValue>> _cache =
diff --git a/srcs/juloo.keyboard2/KeyValue.java b/srcs/juloo.keyboard2/KeyValue.java
index fdb1f25..24eab0b 100644
--- a/srcs/juloo.keyboard2/KeyValue.java
+++ b/srcs/juloo.keyboard2/KeyValue.java
@@ -3,7 +3,7 @@ package juloo.keyboard2;
 import android.view.KeyEvent;
 import java.util.HashMap;
 
-final class KeyValue
+public final class KeyValue
 {
   public static enum Event
   {
diff --git a/srcs/juloo.keyboard2/Keyboard2.java b/srcs/juloo.keyboard2/Keyboard2.java
index 66380e4..daa9ea0 100644
--- a/srcs/juloo.keyboard2/Keyboard2.java
+++ b/srcs/juloo.keyboard2/Keyboard2.java
@@ -23,6 +23,7 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import juloo.keyboard2.prefs.LayoutsPreference;
 
 public class Keyboard2 extends InputMethodService
   implements SharedPreferences.OnSharedPreferenceChangeListener
diff --git a/srcs/juloo.keyboard2/KeyboardData.java b/srcs/juloo.keyboard2/KeyboardData.java
index 557e42f..3cbd4aa 100644
--- a/srcs/juloo.keyboard2/KeyboardData.java
+++ b/srcs/juloo.keyboard2/KeyboardData.java
@@ -14,7 +14,7 @@ import java.util.Set;
 import java.util.function.Function;
 import org.xmlpull.v1.XmlPullParser;
 
-class KeyboardData
+public final class KeyboardData
 {
   public final List<Row> rows;
   /** Total width of the keyboard. */
diff --git a/srcs/juloo.keyboard2/Utils.java b/srcs/juloo.keyboard2/Utils.java
index 0eee945..712c83d 100644
--- a/srcs/juloo.keyboard2/Utils.java
+++ b/srcs/juloo.keyboard2/Utils.java
@@ -7,7 +7,7 @@ import android.view.WindowManager;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 
-class Utils
+public final class Utils
 {
   /** Turn the first letter of a string uppercase. */
   public static String capitalize_string(String s)
diff --git a/srcs/juloo.keyboard2/CustomExtraKeysPreference.java b/srcs/juloo.keyboard2/prefs/CustomExtraKeysPreference.java
similarity index 97%
rename from srcs/juloo.keyboard2/CustomExtraKeysPreference.java
rename to srcs/juloo.keyboard2/prefs/CustomExtraKeysPreference.java
index d007bf7..9d8395f 100644
--- a/srcs/juloo.keyboard2/CustomExtraKeysPreference.java
+++ b/srcs/juloo.keyboard2/prefs/CustomExtraKeysPreference.java
@@ -1,4 +1,4 @@
-package juloo.keyboard2;
+package juloo.keyboard2.prefs;
 
 import android.app.AlertDialog;
 import android.content.Context;
@@ -13,6 +13,7 @@ import android.widget.EditText;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import juloo.keyboard2.*;
 import org.json.JSONArray;
 import org.json.JSONException;
 
diff --git a/srcs/juloo.keyboard2/ExtraKeysPreference.java b/srcs/juloo.keyboard2/prefs/ExtraKeysPreference.java
similarity index 98%
rename from srcs/juloo.keyboard2/ExtraKeysPreference.java
rename to srcs/juloo.keyboard2/prefs/ExtraKeysPreference.java
index 3e8b74b..47ca535 100644
--- a/srcs/juloo.keyboard2/ExtraKeysPreference.java
+++ b/srcs/juloo.keyboard2/prefs/ExtraKeysPreference.java
@@ -1,4 +1,4 @@
-package juloo.keyboard2;
+package juloo.keyboard2.prefs;
 
 import android.content.Context;
 import android.content.SharedPreferences;
@@ -11,6 +11,7 @@ import android.widget.TextView;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
+import juloo.keyboard2.*;
 
 /** This class implements the "extra keys" preference but also defines the
     possible extra keys. */
diff --git a/srcs/juloo.common/IntSlideBarPreference.java b/srcs/juloo.keyboard2/prefs/IntSlideBarPreference.java
similarity index 98%
rename from srcs/juloo.common/IntSlideBarPreference.java
rename to srcs/juloo.keyboard2/prefs/IntSlideBarPreference.java
index 0bdf2c7..bb6bf7d 100644
--- a/srcs/juloo.common/IntSlideBarPreference.java
+++ b/srcs/juloo.keyboard2/prefs/IntSlideBarPreference.java
@@ -1,4 +1,4 @@
-package juloo.common;
+package juloo.keyboard2.prefs;
 
 import android.content.Context;
 import android.content.res.TypedArray;
diff --git a/srcs/juloo.keyboard2/LayoutsPreference.java b/srcs/juloo.keyboard2/prefs/LayoutsPreference.java
similarity index 96%
rename from srcs/juloo.keyboard2/LayoutsPreference.java
rename to srcs/juloo.keyboard2/prefs/LayoutsPreference.java
index d1cffcf..787800c 100644
--- a/srcs/juloo.keyboard2/LayoutsPreference.java
+++ b/srcs/juloo.keyboard2/prefs/LayoutsPreference.java
@@ -1,4 +1,4 @@
-package juloo.keyboard2;
+package juloo.keyboard2.prefs;
 
 import android.app.AlertDialog;
 import android.content.Context;
@@ -12,6 +12,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import juloo.keyboard2.*;
 import org.json.JSONException;
 import org.json.JSONObject;
 
@@ -237,22 +238,22 @@ public class LayoutsPreference extends ListGroupPreference<LayoutsPreference.Lay
 
   /** A layout selected by the user. The only implementations are
       [NamedLayout], [SystemLayout] and [CustomLayout]. */
-  interface Layout {}
+  public interface Layout {}
 
-  static final class SystemLayout implements Layout
+  public static final class SystemLayout implements Layout
   {
     public SystemLayout() {}
   }
 
   /** The name of a layout defined in [res/xml]. */
-  static final class NamedLayout implements Layout
+  public static final class NamedLayout implements Layout
   {
     public final String name;
     public NamedLayout(String n) { name = n; }
   }
 
   /** The XML description of a custom layout. */
-  static final class CustomLayout implements Layout
+  public static final class CustomLayout implements Layout
   {
     public final String xml;
     /** Might be null. */
@@ -269,7 +270,7 @@ public class LayoutsPreference extends ListGroupPreference<LayoutsPreference.Lay
 
   /** Named layouts are serialized to strings and custom layouts to JSON
       objects with a [kind] field. */
-  static class Serializer implements ListGroupPreference.Serializer<Layout>
+  public static class Serializer implements ListGroupPreference.Serializer<Layout>
   {
     public Layout load_item(Object obj) throws JSONException
     {
diff --git a/srcs/juloo.keyboard2/ListGroupPreference.java b/srcs/juloo.keyboard2/prefs/ListGroupPreference.java
similarity index 99%
rename from srcs/juloo.keyboard2/ListGroupPreference.java
rename to srcs/juloo.keyboard2/prefs/ListGroupPreference.java
index 075b38c..e332764 100644
--- a/srcs/juloo.keyboard2/ListGroupPreference.java
+++ b/srcs/juloo.keyboard2/prefs/ListGroupPreference.java
@@ -1,4 +1,4 @@
-package juloo.keyboard2;
+package juloo.keyboard2.prefs;
 
 import android.content.Context;
 import android.content.SharedPreferences;
@@ -9,6 +9,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import java.util.ArrayList;
 import java.util.List;
+import juloo.keyboard2.*;
 import org.json.JSONArray;
 import org.json.JSONException;
 
diff --git a/srcs/juloo.common/SlideBarPreference.java b/srcs/juloo.keyboard2/prefs/SlideBarPreference.java
similarity index 99%
rename from srcs/juloo.common/SlideBarPreference.java
rename to srcs/juloo.keyboard2/prefs/SlideBarPreference.java
index b41448b..cacf37e 100644
--- a/srcs/juloo.common/SlideBarPreference.java
+++ b/srcs/juloo.keyboard2/prefs/SlideBarPreference.java
@@ -1,4 +1,4 @@
-package juloo.common;
+package juloo.keyboard2.prefs;
 
 import android.content.Context;
 import android.content.res.TypedArray;