The app which is linked from the readme and in the teaser to BCI 101 on the page http://learn.neurotechedu.com/lessons/ seemingly doesn't exist anymore. Neither does the link work nor is an app with such name to be found with a search in the Google Play store. I would suggest to remove the link.
EDIT: I found its project page here: https://github.com/NeuroTechX/eeg-101 and they recommend in the README a successor there. Maybe it should be replaced with that one.
The app which is linked from the readme and in the teaser to BCI 101 on the page http://learn.neurotechedu.com/lessons/ seemingly doesn't exist anymore. Neither does the link work nor is an app with such name to be found with a search in the Google Play store. I would suggest to remove the link.
EDIT: I found its project page here: https://github.com/NeuroTechX/eeg-101 and they recommend in the README a successor there. Maybe it should be replaced with that one.