What we learned testing our group trip app on a six-country Interrail trip in Europe

This summer a few of us did Interrail across six countries. We won DiscoverEU tickets and had no exact plan, just a group chat that filled up fast with screenshots, booking codes, and the classic "wait, who paid for the hostel?"

A few things stuck with us more than any single stop did:

1. Booking chaos scales faster than the trip. By day three the group chat wasn't a place to talk anymore; it was a filing cabinet nobody could search. Every new booking meant someone scrolling back through forty messages to find the confirmation, and often it's not even there.

2. Money gets political fast. Nobody wants to be "that person" chasing a friend for 80 kr, so people just don't. It piles up quietly until the last night, when someone finally does the math and everyone's memory of who paid for what turns out to be wrong.

3. "We'll settle up later" always means "we'll argue about it later." The longer costs go untracked, the more everyone's version of events diverges.

4. The best group trips are the ones where money is boring. The moment nobody has to think about who owes who, the trip is just the trip.

By the second week we'd basically stopped using the group chat for logistics. Instead we started photographing receipts and forwarding confirmation emails into a shared trip timeline, with everything landing on its own line by category and costs tallied automatically. It worked well enough that we kept building on it after we got home. It's called Deline, live on iOS since August.

Curious if anyone else has found their own fix for the money side of group trips, or if it's just something everyone quietly suffers through.

P.S. We're looking for Android testers. Deline is already free on the App Store, and now it's Android's turn. If you're on Android and want in, whether you have a trip coming up or just want to poke around, sign up with your email on our website and we'll send you a link. And if you know someone on Android who's always the one planning the group trip, please send this to them. It helps us a lot. Try it out: deline.dev

Really interesting point about group chats turning into “filing cabinets” during a trip. I’ve seen the same thing when planning travel — confirmations, costs and small decisions quickly get scattered everywhere. Bringing bookings and expenses into one shared timeline sounds genuinely useful, especially for group trips. Looking forward to seeing how the Android version develops.

Hi Leo, I love that you road-tested this and shared your observations here. It really validates why apps like this are still needed.

I run a travel SEO and digital strategy consultancy, so I couldn't resist a look at the app and site. You've clearly put real thought into it: the design, the comparison articles, sourced tables and FAQ blocks.
A few things that could help you:

Add app schema (SoftwareApplication) to the homepage, so search and AI engines clearly understand its a free app and where to download it etc.
Make the rename from Tripline explicit in your site's organisation data "formerly Tripline" line and update the old socials in the schema. An about page here on this would help along with your authority too.

I've got a few more specifics I'm happy to share privately, free, if it's useful. Feel free to message me.

Otherwise, wishing you success!