This app was mentioned in 1 comment, with an average of 6.00 upvotes
E-park, for your car in case you rent one : https://play.google.com/store/apps/details?id=com.setex.epark
Google translate in case you have issues with Spanish:. https://play.google.com/store/apps/details?id=com.google.android.apps.translate
And the "Madrid Metro|Bus|Cercanias" that has been mentioned