ChartMogul is the best thing since sliced bread. It integrates with App Store Connect and allows you to visualize all your analytical data so much easier such as LTV, churn, run rate, MRR, and average sale price. It makes quarterly reports a breeze.
Notion is absolutely phenomenal. It's essentially Slack but for all your notes. You can organize everything in separate sections, include to-do lists items, spreadsheets, emojis, covers, and so much more. It's a great place for all your notetaking needs.