• The most important usability dimension for this app is Safety. Errors in transactions can be costly to both parties, and cause irreperable financial damages.
• Errors. (Safety) Errors in calculations and/or categorizations are very likely to happen, and would go unnoticed by users.
• Navigation. (Safety and Learnability) With spreadsheets in general, it is very hard to navigate among the cells in the sheet, and entering a transaction in the wrong column could be very likely (especially as you scroll and the position of columns changes).
• Categorizations. (Learnability and Efficiency) The categorization of transactions is not intuitive, and it takes the user some thinking to figure out under which column to record them.
• Entering a transaction. (Safety and Efficiency) Overall, entering all the details of the transaction by hand is not time-efficient and also prone to human error (as there are no preset options and/or type checking).
• Lack of information. (Efficiency) When it comes to expenses, additional information, such as receipts and the date of transactions, may come in useful.