I built Costman trying to solve a very personal problem.
My parents aren t good with technology and have mostly been left behind by it. They keep every receipt, write expenses by hand, and still struggle to answer simple questions like where they pay more for the same groceries or whether prices actually went up or it just feels that way .
Costman helps you understand your money by chatting on WhatsApp. Literally chatting. Log expenses naturally as you spend, or dump everything later in the day. Organize them into categories with budgets, then ask real questions like where you pay more for the same items, how prices changed, or which categories spike on weekends. No apps. No spreadsheets. No signup. Just ask Costman about your money and get clarity when you need it.
I wanted something they could use without learning an app or dealing with spreadsheets. Something that felt like sending a message something they re already experts at but still gave them useful answers later.
The hardest part was making it flexible enough so you don t have to log things perfectly, yet still be able to ask meaningful questions about spending patterns and price differences.
In what other ways could Costman be useful to you?
Well, if any of these situations sound familiar to you...
You don t really know where your money goes each month
Those small daily purchases coffee, snacks, taxis feel harmless on their own. But together, they can quietly eat up a big chunk of your income without you noticing.

You wish your expenses were organized, but spreadsheets feel unrealistic
In a time-poor world, keeping spreadsheets updated and analyzing them feels like a job on its own. You want something just as useful, but more natural like an Excel in your pocket that you can actually talk to. Simple, fast, and always with you.
How does it work?

Three simple steps to understand your money.

1 Create categories
Set up categories with a name and a budget. Adjust, edit, or delete them anytime as your spending changes.