Walnut is a expense tracker which am using from last 6 month. It tracks your expense by text message which you get to your mobile if any bank transaction is done. Basically it reads your bank text message and no input is required for this. Even this recognize some wallet transactuin detail also. It divide expense and shows how much we spent for shopping, withdrawal, Sent amount in each categeory seperately. App is very user friendly without any input it works. It reminds your phone bill, water bill, credit bill card payment. After demonetizationa new feature is added which is Atm founder from which we can come to know which atm have cash nearby you. It wont ask for your any personal password or pin of any related bank account, so I think this app is very safe and secure to use. At end of month its become very easy to track my expense and I can avoid more money tight situation.