MeMo: MeMo is a set of entertaining exercises to train cognitive functions and motivation.
It is open access and free.

More information on MeMo: http://www.memory-motivation.org/home-3/

Efficacy of a Web App for Cognitive Training (MeMo) Regarding Cognitive and Behavioral Performance in People With Neurocognitive Disorders: Randomized Controlled Trial
J Med Internet Res 2020;22(3):e17167doi: 10.2196/17167