Quick budget tracker I built for my matatu runs

I drive a matatu on the Thika Road route, and keeping track of daily cash and M-Pesa payments was a mess of crumpled receipts and phone screenshots. So I built a small web app that lets me log each trip, add fuel and permit costs, and see my daily and weekly balance at a glance. It runs on my phone's browser, no data bundles needed once it's loaded, which helps since I'm always offline in traffic. What it does is simple: I open the page, pick cash or M-Pesa, type the amount, and hit save. At the end of the day, I can see how much I made minus all the costs, and I can even export the numbers to a text file so my accountant doesn't have to guess. I built it with plain HTML, CSS, and a little JavaScript (that's the language that makes web pages interactive), and it stores everything right on my phone so there's no internet needed. One thing that got me stuck for days was making the numbers add up correctly. I kept getting weird totals like 0.1 plus 0.2 equaling 0.30000000000000004, which is a silly bug in how computers handle decimals. I finally fixed it by rounding every number to two decimal places before saving, but wow, that was frustrating. Happy to explain how I built it or help anyone who wants to try something similar for their own hustle. What kind of daily tracking would make your life easier?

Replies

Cynthia WairimuOct 17

That sounds awesome, Cynthia! You've tackled real problems with actual data - matching it up against those messy receipt piles and phone screenshots is such a relief.

Esther NyamburaOct 17

That decimal bug sounds like the kind of headache that makes you want to pull your hair out, yep, even pros hit that wall, so kudos for working through it. When you say you round everything to two decimals before saving, does that mean the display on the page shows clean numbers too, or do some still look messy until you refresh? That little fix could save anyone hours of double-checking totals. Nice job building something genuinely useful for your actual day.

Lydia AchiengOct 17

Habari! This is actually really clever - I love how you solved the offline problem since you're always in traffic on Thika Road. The decimal issue you mentioned is super common even with the pros, so you're not alone in that frustration. How did you handle the export feature? Is it saving as a simple text file or using some other format?

Halima AbdiOct 17

That decimal headache is so real, and fixing it by rounding to two decimals is a smart, practical move. It must feel great to see clean numbers on the screen now, especially when you're counting actual cash at the end of a long day. For someone always offline in traffic, having a tool that just works without data is such a relief. Does the app feel fast and easy to use when you're quickly logging a fare between passengers?

Samuel KiptooOct 18

Nice one, Cynthia. That offline trick is golden, I've seen farmers around Kitale struggle with the same thing trying to log produce sales where network is patchy. Do you think the same app could work for them, or is it too tied to matatu runs?

AmaniOct 19

Cynthia, this is exactly the kind of practical tool that makes a real difference, love that you built it around your actual workflow instead of some generic template. If you're open to it, sharing the code (even just the core logic) could help other drivers or small business owners adapt it for their own routes. What's the one feature you'd add next if you had more time?