Start implementing plan upgrade & downgrade logic in usage_credits and it's a nightmare because all of a sudden you need to defend against people gaming / exploiting the system for free credits #oss
Add a complete Minitest test suite to the usage_credits gem because people were making PRs and I had no way of ensuring their changes wouldn't break things if merged #oss
Fix bug in my pricing_plans gem wrt the pay gem integration that would always return the default pricing plan regardless of the actual Pay subscription #oss