You are probably much better off keeping the $10 you would spend on this app for paying for Internet in the nearest etecsa. The place we tried which was starred as recommended on this app was $5-10 more expensive than listed with misleading amenities (including language spoken). It was both the most expensive and the worst place we stayed in Cuba! If the app had a way of updating saved data to include, say, the five most recent reviews as of last internet access, this might help make the app more useable but I would trust reccommendations from your casa owner first.
Babebabeba about Cuba Casa Directory, v1.24