This is an idea to be able to group your transactions into an user defined group.
For example you could create an event called ‘Weekend trip to London’, then tap on the transactions you made when you were there and add them to this event. It would make it easier in the future to look back at what you spent there.
Or another way would be at the start of the weekend to create your ‘Weekend in London’ group, then all transactions automatically go into that event. At the end of the weekend you could ‘End event’ and the group closes. You could also set a budget at the start of the event and get updates how much you have spent/have left in your budget.