PayPal Widget is the best and simplest way to keep an eye on your PayPal account balance, available funds, and pending transactions. It shows your money in a widget, so you can keep it on your home screen and get notified whenever there is an available balance. It also allows you to set a threshold for notifications so you don't get inundated with messages.

If you want to be notified when your money is deposited or withdrawn, you can set up a transaction log in the Settings tab of the PayPal Widget app. You will then be notified about each and every transaction you make.