Yes! ZanZan travel is free to download and run for both Android and iOS devices. We do plan to add premium in-app purchases in the future while keeping core functions intact.
Inside your created trip/stop you'll have a "Common Fund" button. Easily add scanned receipts or paid bills and specify the group members involved. The app mathematically calculates who owes what to whom at the end of the trip.
Absolutely. We rely on an obfuscated storage and your visual attachments (passports, flight tickets) will be available offline protected by the sandbox nature of your Phone OS.
From Settings panel you'll be free to export your data footprint, delete your historical activity, or trigger a full wipe of your targeted DB records in compliance with GDPR guidelines.