This app was mentioned in 1 comment, with an average of 3.00 upvotes
this is easy. just log in to Kik, go into titanium backup, find kik and choose "restore data only"
then your messages should be there, while still logged in. or, you could disable your internet access and look through the messages offline. then it won't log you out.
alternatively, you could use this app to look at old messages, however it won't restore them back into the app.