Google does publish an app called Field Trip that they acquired from Niantic. It tells you about historical tidbits for the place around you. Doesn't seem to have been updated lately.
I used Field Trip for a while and really liked it when walking around in an unfamiliar city. As you say, as you went along, it would point out interesting facts, landmarks, etc. Then I noticed that its focus seem to change to "You're near Hardees! Here's a two for one coupon!" I deleted the app and never tried it again.