As someone who worked in the area of Intelligence training I am very, very skeptical. For example, there was a burst of optimism about training working memory through Dual N-Back tasks, bought about by a revolutionary paper from Jaeggi et al. Then... not quite nothing but close.

I suspect there's a reason that no braining activity, ever, has been consistently shown to improve intelligence at the construct level. It may be that more specific capacities related to intelligence (like working memory) are improved, and that these affect life outcomes and practical capacity to grasp concepts etc, but this has yet to demonstrated to my satisfaction.