Thanks for the idea, we do want to build a nice use case around bill splitting (notifications, shared receipts, etc.). It’s on our roadmap 
Regarding manually add money that people paid you in cash I do see that as an actual need but it scares me a bit. The idea of ever let you add “manual” stuff so you can arbitrarily mess with your feed and reports could be a huge rabbit-hole. We haven’t explored it yet but, to me, it seems like the kind of thing where the trade-off of complexity/power may be not really worth it. We’ll keep it on mind though 