By Graham K. Rogers

A recent arrival in the iTunes App Store in this part of the world is a free app from a developer that I know better for its hardware: Studio Neat. They have come up with a useful app for adjusting the speed of video. Slow Fast Slow is a free app (of course, now we "Get" these in the App Store) that works with videos already created on the iPhone.

When first opened, there is a brief message from the developers that can be scrolled right into a series of screens with video pages (edited with Slow Fast Slow) that show their their main product, the Glif. I had one of these initially for the iPhone 4 (and 4S), but the one I bought later for the iPhone 5s is adjustable so works on the iPhone 6 as well.

At the main screen, there is a + icon to add and work on a video. There are two sources available: Slo-Mo Videos and Other Videos. The selection in the Other section included examples I had made with SloPro and exported to the iPhone library as well as non-slo-mo videos.

Initially, the Slo-Mo Videos section was empty as I have not used this feature of the iPhone camera. Once I had created a couple, these were made available for use.

The editing screen is split with the video in the top half and clear controls at the bottom. Using the fingers, it is possible to slide the editing points up and down, to increase or decrease the speed of any (or all) of the video.

While the editing screen is open, by pressing on a specific area, a new point may be added. A text box appears above a circular point with the words, Add Point. When the box is tapped, the point is confirmed and created: the circle becomes solid.

There are a number of other controls above the edit that are of value in the process:

• A back arrow returns the user to the video selection screen;
• A tuning fork icon adjusts sound output
  • Normal
  • Echo
  • Off
• A long arrow allows the user to reverse the video (there is a delay for rendering)
• Export is to the Photo Library with two options: Square; or Landscape (19x9)

Once a video exists, Slow Fast Slow makes it really quick and easy to adjust the speeds and make a new video available for use.

A note on the Glif:

It was clear to me when the first olloclip lenses appeared that use of the macro, especially, would need a tripod. This type of attachment is also useful when making time-lapse, stop motion or slo-mo videos as the camera (iPhone) is best held still. The apps I use for these effects are iTimeLapse, SloPro (which can go up to 1000 fps, compared with the iPhone's 240 fps), and Stop Motion.

I looked at a number of options for a tripod solution and the Glif seemed the best for me. It clamps the iPhone which can then be attached to a normal tripod. As well as a normal sized tripod, I found a mini-version in a local mall here for 280 baht (less than $10) although the welded screws need replacing now. It was cheap enough to be able to buy another. The Glif, however, does not need replacing and allows me to suspend the iPhone safely (it takes some confidence to do this) as well as attach it to a tripod.

Slow fast Slow is billed as an app for the iPhone. It is not optimised for the iPad but will install and run on that device, although in the non-universal x1 and x2 screen sizes.

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand where he is also Assistant Dean. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs. He is now continuing that in the Bangkok Post supplement, Life.