Periscope
https://itunes.apple.com/app/id972909677
Recommend
https://itunes.apple.com/ca/app/recommend/id581172353?mt=8
GetYourGuide
https://itunes.apple.com/de/app/getyourguide-tours-activities/id705079381?l=en&mt=8
https://play.google.com/store/apps/details?id=com.getyourguide.android&hl=en