Play online games with your friends. Have a look at what is available on the app stores on your phones or go to gaming platforms such as Steam to browse multiplayer games. Kast is a good screen capture app that could be used to share your gameplay.
Go on a virtual trip together. Museums, zoos, aquariums and more are offering livestreams and virtual tours. Some links are available here and there are plenty more to be found online. Use a video chat platform to make this a group trip.
Organise a film night with your friends using Netflix Party. You can watch a programme together and join a group chat to talk. Netflix Party lets you synchronize Netflix watching across device/locations and adds chat feature between a group
DIY Science: anyone can be an engineer with Siemans who have produced quick and simple experiments that KS2 children could do simultaneously in their homes and watch how their friends are getting on at the same time/chat with each other.