A bubble send off. If its at night use sparklers. Be sure to warn your photographer in advance this happens quick and can easily be missed. Not to mention camera setting need to be changed and maybe a little set up as well. Because its hard to focus through bubbles, and sparklers are tricky and may require a tripod and a flash.
The Wedding party app. This is a free mobile app for iPhone and Android. It allows your friends to upload all their photos of you two in on place, and share seamlessly via their phone or computer. Photos are chronological so there is a timeline of photos from the engagement to the wedding day. https://www.weddingpartyapp.com/
They each held a shoe, one from him and one from her. Their friends asked them questions like "who is the better looking" or "who is most likely to..." and without seeing eachother held up the "proper" shoe. Its best played asking questions that will get him in trouble. :-)