Great Idea! A nicer touch would be to provide option to create multiple saving goals, and conditional saving into them automatically. for eg,
goal 1 - car; save into this basket whenever I'm paying for fuel, air/bus/train tickets.
goal 2 - smartphone; save into this basket whenever the spending is via online POS - amazon, swiggy, uber, etc
goal 3 - emergency fund; save into this basket whenever paying rent, buying groceries.
Obviously, the baskets will be virtual and abstracted over a single savings account.
The saving criteria can be selected by user. using a wide range of spend categories.