From Google Play Games to Our Own Friends System

From Claude Code: We tried adding friends through Google Play Games. You needed a GPG account, the other person needed a GPG account, and you had to become friends there first before the game could see the connection. It worked — mostly — but it came with a long list of things we couldn't control. What was wrong with GPG friends Google Play Games is Android-only. The moment we start thinking about iOS, the entire social layer would need to be rebuilt from scratch around Game Center. Two separate friend graphs, with no way to connect them. An Android player and an iOS player couldn't be friends at all. It also required more than just Spare Squares. You had to have GPG installed and set up, tied to a Google account. That's a reasonable ask for competitive features, but asking someone to maintain a Google gaming profile just to share a puzzle game with a friend felt like the wrong trade. And practically speaking, the GPG SDK came with real integration weight: a sizeable library, Gradle configuration constraints, and a stub file we had to maintain to prevent a crash at startup. Every SDK upgrade was a potential build problem. We removed it in version 397. The new friends system The replacement is built entirely on invite links. Every Spare Squares account has a permanent invite token — a 10-character code that looks like ABC-12345-XY. You can share it two ways: as a URL (https://spare-squares.com/friend/ABC12345XY) or just the formatted code itself. The URL opens the app directly if it's installed, or shows an install page if it isn't. The code can be typed into the Add a Friend field manually. That's the whole flow. No external account. No platform handshake. No mutual acceptance ritual. Because the system lives entirely in Spare Squares accounts, it works the same on any platform. An Android player and an iOS player can exchange tokens and become friends before iOS even ships. The social graph is ours to extend as the game grows. What friends unlock Once you're connected, a Friends leaderboard tab shows how your scores compare to the people you've added — both all-time and this month. Friend notifications let you know when someone you know hits a personal best on a Solo board, scores perfectly, finishes first in a Ranked game, or earns an achievement. You can control whether you receive these in Settings. The Friends screen also shows your own invite link and code at all times, so sharing is always one tap away. Why the token approach We considered a username-search system, but that creates a discoverability problem: you can find anyone, which means strangers can find you. The token model means friendship is always opt-in on both sides. You share your link with people you actually want to connect with. If you want to start fresh, you can regenerate your token — existing friendships stay, but the old link stops working. It's a small design decision, but it reflects something we care about: the game should connect people who already know each other, not serve as a discovery platform.