How to improve working memory
Working memory improves mainly through practice on the specific task you care about, plus the ordinary things that protect thinking in general: enough sleep, less divided attention, and practice spaced out over days. There is no shortcut that reliably transfers to unrelated tasks.
What working memory actually is
Working memory is the small amount of information you can hold and actively work with at once, such as a phone number while you find a pen, or a running total while you do mental maths. The idea was formalised in 1974 by Alan Baddeley and Graham Hitch, who split it into a system for holding information and a separate system for manipulating it, rather than treating memory as one single store.
Does training it help
Working memory training programmes reliably improve performance on the trained task. A 2013 meta-analysis of the training literature found short-term gains on the practised task, but did not find good evidence that those gains transferred to other measures, such as reasoning or general problem-solving.
That does not make practice worthless. Getting better at holding and updating information under pressure is a real skill in its own right, and a visuospatial task like remembering a sequence of positions is a well-established way to exercise it. Philip Corsi built one such task in 1972: tapping out a sequence of blocks and asking someone to repeat it back. The longest sequence someone can repeat correctly, their block span, is still used as a working-memory measure today.
Habits that help more than any app
Outside of any task, the things that most reliably support working memory are unglamorous: enough sleep, cutting down on multitasking while you are trying to hold something in mind, and spacing practice out over several days rather than cramming it into one long session. None of this is specific to Brain Gym. It is just how attention and memory work.
Sources
Baddeley, A. D., and Hitch, G. (1974). Working memory. In G. H. Bower (Ed.), The Psychology of Learning and Motivation (Vol. 8, pp. 47-89). Academic Press.