Use Community Toolkit to animate a FontIcon continuously. Speed can be adjusted.

UWPCommunityToolkitContinuousRotations.cs

private async Task animateSyncingIcon()
        {
            nowSyncing = true;
            var centerX = (float)syncIcon.ActualWidth / 2;
            var centerY = (float)syncIcon.ActualHeight / 2;
            const int maxRotation = 360;
            double rotationsToPerform = 10;
            double rotationsPerSecond = (double)(1 / rotationsToPerform);
            var duration = (float)(rotationsPerSecond / maxRotation);
            int rotation = 1;
            while (nowSyncing)
            {
                if (rotation == maxRotation)
                {
                    await syncIcon.Rotate(0, centerX, centerY, 0).StartAsync();
                    rotation = 0;
                }
                await syncIcon.Rotate(rotation, centerX, centerY, duration).StartAsync();
                rotation += (int)rotationsToPerform;
            }
        Fioe