To watch slideshows, open the FamilyAlbum app and go to the most recent month on the Album screen. A slideshow will be available if at least 3 uploads were taken on the same day in a previous month/year.
By subscribing to FamilyAlbum Premium, you can continue your slideshow into later dates by tapping “Next day”. You’ll also get access to random Highlights if you’ve uploaded at least one photo or video between a week and six months ago.