Sino nagbayad?
Even remembers. One person fronts the cost for the group, everyone sends their share over GCash, and Even works out the exact number each person owes and keeps the payment screenshot as proof.
Only one person needs the app.
Everyone else gets a link. No install, no signup, no account. They see one number, who to send it to, and a box to drop the receipt into.
Even never holds or moves money. Every peso moves inside GCash between two people who already know each other.