If you have automatic updates on the app should update - you will know it has as the icon will be blue with the Ramblers R and have the word Ramblers
If you do not have automatic updates turned on, or if you wish to do this manually
go to the Apple Store Click here to get it on the App Store
or Play Store Click here to get it on Google Play
Or search in the stores using 'Ramblers' and click on update.