android/gradle.properties

 org.gradle.jvmargs=-Xmx1536M
 android.useAndroidX=true
 android.enableJetifier=true
-app.versionName=0.0.8
-app.versionCode=8
+app.versionName=0.0.9
+app.versionCode=9

lib/provider/data.dart

@@ -4,6 +4,9 @@ import '../entities/tile.dart';
 
 class Data extends ChangeNotifier {
 
+  // application configuration
+  int _tilesCount = 3;
+
   // application data
   List _images = [];
   String _image = '';
@@ -19,6 +22,13 @@ class Data extends ChangeNotifier {
     notifyListeners();
   }
 
+  int get tilesCount => _tilesCount;
+
+  set updateTilesCount(int value) {
+    _tilesCount = value;
+    notifyListeners();
+  }
+
   List get images => _images;
 
   set updateImages(List value) {

lib/screens/home.dart

@@ -12,9 +12,6 @@ import '../utils/get_images_list.dart';
 class Home extends StatelessWidget {
   static const String id = 'home';
 
-  int _linesCount = 4;
-  int _columnsCount = 4;
-
   double _selectorImageSize = 200;
   double _tipImageSize = 100;
   double _tileImageSize = 80;
@@ -84,6 +81,43 @@ class Home extends StatelessWidget {
     );
   }
 
+  FlatButton _buildTilesetSizeSelectorItem(Data myProvider, int value) {
+    BoxDecoration border =
+      myProvider.tilesCount == value
+      ? BoxDecoration(
+        borderRadius: BorderRadius.circular(4),
+        border: Border.all(
+          color: Colors.blue[100],
+          width: 4,
+        ),
+      )
+      : null;
+
+    return FlatButton(
+      child: Container(
+        padding: EdgeInsets.all(5),
+        decoration: border,
+        child: Text(value.toString()+'x'+value.toString()),
+      ),
+      onPressed: () { myProvider.updateTilesCount = value; },
+    );
+  }
+
+  Container _buildTilesetSizeSelector(Data myProvider) {
+    return Container(
+      child: Center(
+        child: Row(
+          mainAxisAlignment: MainAxisAlignment.center,
+          crossAxisAlignment: CrossAxisAlignment.center,
+          children: [
+            _buildTilesetSizeSelectorItem(myProvider, 3),
+            _buildTilesetSizeSelectorItem(myProvider, 4),
+          ],
+        ),
+      ),
+    );
+  }
+
   Future<List<Tile>> splitImageInTiles(Data myProvider) async {
     String imageAsset = getImageAssetName(myProvider.image);
     Uint8List imageData = (await rootBundle.load(imageAsset))
@@ -92,12 +126,12 @@ class Home extends StatelessWidget {
     imglib.Image image = imglib.decodeImage(imageData);
 
     int x = 0, y = 0;
-    int width = (image.width / _linesCount).round();
-    int height = (image.height / _columnsCount).round();
+    int width = (image.width / myProvider.tilesCount).round();
+    int height = (image.height / myProvider.tilesCount).round();
 
     List<Tile> tiles = List<Tile>();
-    for (int i = 0; i < _linesCount; i++) {
-      for (int j = 0; j < _columnsCount; j++) {
+    for (int i = 0; i < myProvider.tilesCount; i++) {
+      for (int j = 0; j < myProvider.tilesCount; j++) {
         tiles.add(
           Tile(
             Image.memory(
@@ -136,9 +170,9 @@ class Home extends StatelessWidget {
         width: 2,
       ),
       children: [
-        for (var row = 0; row < _linesCount; row++)
+        for (var row = 0; row < myProvider.tilesCount; row++)
           TableRow(children: [
-            for (var col = 0; col < _columnsCount; col++)
+            for (var col = 0; col < myProvider.tilesCount; col++)
               Column(children: [tiles[tileIndex++].widget(myProvider)]),
           ]),
       ]
@@ -236,9 +270,11 @@ class Home extends StatelessWidget {
           _myProvider.image == ''
           ? Text('')
           : IconButton(
-            icon: const Icon(Icons.arrow_left_outlined),
-            onPressed: () => resetGame(_myProvider),
-          ),
+              icon: const Icon(Icons.arrow_left_outlined),
+              onPressed: () => resetGame(_myProvider),
+            )
+          ,
+          _myProvider.image == '' ? _buildTilesetSizeSelector(_myProvider) : Text(''),
         ],
       ),
       body: SafeArea(