This app was mentioned in 1 comment, with an average of 2.00 upvotes
Have a look at Crowdmap from Ushahidi (http://www.ushahidi.com/product/crowdmap/). Great OpenSource project created for collecting geo-coded data in Epidemiology (or stories for Journalism). Got a corresponding mobile app: https://play.google.com/store/apps/details?id=com.ushahidi.android.app&hl=en
Not sure if this would suit your use-case. As it would probably need too much data entry, but you can even attach images to POI's.