move names not starting with a letter at the bottom

app/src/main/kotlin/com/simplemobiletools/contacts/activities/MainActivity.kt

@@ -64,6 +64,7 @@ class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
         }
 
         contacts_fastscroller.updateBubbleColors()
+        contacts_fastscroller.allowBubbleDisplay = config.showInfoBubble
         updateTextColors(contacts_holder)
     }
 
@@ -127,7 +128,6 @@ class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
                 contacts_list.adapter = this
             }
 
-            contacts_fastscroller.allowBubbleDisplay = config.showInfoBubble
             contacts_fastscroller.setViews(contacts_list) {
                 val item = contacts.getOrNull(it)
                 contacts_fastscroller.updateBubbleText(item?.getBubbleText() ?: "")

app/src/main/kotlin/com/simplemobiletools/contacts/models/Contact.kt

@@ -11,7 +11,13 @@ data class Contact(val id: Int, var name: String, var number: String, var photoU
     override fun compareTo(other: Contact): Int {
         var result = when {
             (sorting and SORT_BY_NUMBER != 0) -> number.toLowerCase().compareTo(other.number.toLowerCase())
-            else -> name.toLowerCase().compareTo(other.name.toLowerCase())
+            else -> if (name.first().isLetter() && !other.name.first().isLetter()) {
+                -1
+            } else if (!name.first().isLetter() && other.name.first().isLetter()) {
+                1
+            } else {
+                name.toLowerCase().compareTo(other.name.toLowerCase())
+            }
         }
 
         if (sorting and SORT_DESCENDING != 0) {