Apps to track spend

Hi all! My partner and I are making average money but we just cant seem to understand how to save more. We have considered a side hustle, but dont know where to start or how to find the time after our 9-7 (should be 9-5 but we can never stop at 5pm)

As a start point, we want to track how we are spending to know ways to save more. Any apps you use to track spends? Ideally the app would be shared between us so we get a sense of collective expenses.

Today is March 1 so figured its the best day to start this little project. Thanks in advance