Looks nice and clean. Would be nice to add a page that visualizes expenses over a period of months.
The visualisation happens in the spreadsheet – https://docs.google.com/spreadsheets/d/1eYrQf0xhs2mTSWEzQRfS... – check out the Current and Previous sheet. I like to use it on the spreadsheet side to keep the app simple and I use bigger screen for the analysis anyway.