To boot a user from your group but still allow them to join again, follow these steps:
- Open the Kik app.
- Select the group chat from your chat list.
- Tap on the group chat to open it.
- Tap on the Group Name at the top of the group chat to go to the Group Info Screen.
- Tap the profile photo of the person you'd like to boot out of your group.
- Select Remove from Group.