Tested locally and seems to work as expected. Thanks for the update.

Merged in johannski/unity-ui-extensions/ScrollSnapRefactoring (pull request #14)

ScrollSnapRefactoring

Scripts/Layout/HorizontalScrollSnap.cs

@@ -238,7 +238,7 @@ namespace UnityEngine.UI.Extensions
             if (_scroll_rect.horizontal)
             {
                 var distance = Vector3.Distance(_startPosition, _screensContainer.localPosition);
-                if (UseFastSwipe && distance < panelDimensions.width + FastSwipeThreshold && distance >=1f)
+                if (UseFastSwipe && distance < panelDimensions.width && distance >= FastSwipeThreshold)
                 {
                     _scroll_rect.velocity = Vector3.zero;
                     if (_startPosition.x - _screensContainer.localPosition.x > 0)
@@ -252,6 +252,6 @@ namespace UnityEngine.UI.Extensions
                 }
             }
         }
-         #endregion
+        #endregion
     }
 }

Scripts/Layout/ScrollSnapBase.cs

@@ -64,7 +64,7 @@ namespace UnityEngine.UI.Extensions
         [Tooltip("Fast Swipe makes swiping page next / previous (optional)")]
         public Boolean UseFastSwipe = false;
 
-        [Tooltip("Offset for how far a swipe has to travel to initiate a page change (optional)\nDefault is the panel dimensions")]
+        [Tooltip("Offset for how far a swipe has to travel to initiate a page change (optional)")]
         public int FastSwipeThreshold = 100;
 
         [Tooltip("Speed at which the ScrollRect will keep scrolling before slowing down and stopping (optional)")]
@@ -314,8 +314,8 @@ namespace UnityEngine.UI.Extensions
         internal int GetPageforPosition(Vector3 pos)
         {
             return _isVertical ?
-                -(int)Math.Round((pos.y - _scrollStartPosition) / _childSize) :
-                -(int)Math.Round((pos.x - _scrollStartPosition) / _childSize);
+                (int)Math.Round((_scrollStartPosition - pos.y) / _childSize) :
+                (int)Math.Round((_scrollStartPosition - pos.x) / _childSize);
         }
 
         /// <summary>