Replace action sheet icon

ios/Application/Assets.xcassets/ic_more.imageset/Contents.json

@@ -0,0 +1,23 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "baseline_more_horiz_black_24pt_1x.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "baseline_more_horiz_black_24pt_2x.png",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "filename" : "baseline_more_horiz_black_24pt_3x.png",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

ios/Application/Frontend/MainScreenController.swift

@@ -113,7 +113,8 @@ class MainScreenController: UITableViewController, MainScreenDataSourceListener
         self.title = "Habits"
         
         self.navigationItem.rightBarButtonItems = [
-            UIBarButtonItem(barButtonSystemItem: .bookmarks, /* TODO: Replace by appropriate icon */
+            UIBarButtonItem(image: UIImage(named: "ic_more"),
+                            style: .plain,
                             target: self,
                             action: #selector(self.onMoreActionsClicked)),
             UIBarButtonItem(barButtonSystemItem: .add,