Spending 23 days in Europe there are many helpful apps you can use for navigating, translating, and keeping in contact with people on your trip.
The IBS app was very useful to me on my trip. I used it every day to stay on top of the itinerary and to know what we were doing next. Program leaders also upload their pictures to this app.
We used WhatsApp every day to stay in contact with everyone and to find out what others were doing on our free days/nights. Your program leaders are also in the group chats and will remind you about when you will depart for business seminars. This app is a must to get for your trip.
Google Translate was very helpful. There is a feature on this app where you can take a picture and it will translate it for you. I would use this when eating out, and needed help reading menus, or if you are having trouble communicating with Europeans.
Venmo was used very often in my group. When eating out in Europe, it is not the norm to get separate checks like it is in the United States, especially if you have a larger group. It was much easier for one person to put it on a card and then everyone else Venmo them.
On your trip, you will take a lot of pictures and videos and I recommend making a Google Drive folder, so you and your friends can upload your pictures to it.
This app is for the electric scooters, and we used them in Paris and London. It was so much fun riding around on these and super convenient. Keep in mind, riding for about 35 minutes is about 10 euros.