I hacked my own behavior to start logging expenses immediately after spending
My frustration until now was the gap between purchasing something at the store and then waiting to go home to log the expense and usually most days I would just forget about it until I really sat down for an hour or so and go through every transaction I made on every single card. I was doing this biweekly via spreadsheets but I really tried all the possible ways to budget honestly. From the notes app, to pen and paper to taking out cash and putting them in envelopes, to apps but every thing still didn't unblock me to log it in the moment.
I studied app psychology very passionately in my early career years and for context most apps, ie: Instagram, TikTok, FB are designed based on the attention economy and keep you inside them as long as possible by mechanics like infinite scroll, streaks, dopamine loops borrowed straight from casino psychology. I wanted to build the opposite. An app you open, use for 3 seconds, and close.
So I built the opposite, Reign, where the sole purpose is to allow me to log the expense as soon as I pay for something. It hides my numbers with a single tap so that I don't have to worry about anyone looking over at my phone with my finances exposed. I read that is usually takes 21 days to do it mindlessly and that's when the habit is strong and I think I'm almost there as I been doing this for about 2 weeks now. What I didn't realize is that it's extremely satisfying seeing the individual logs build up (reminds me of the 1% a day rule that Atomic Habits taught me) so that I have an overview of how much I spent so far, and the days that I spent the most and the least and also days that I haven't spent anything.
For context I am a software engineer that has about 6 YOE who worked at startups with 10-20 ppl to organizations with 1000+ ppl and I wanted to make something to make my life easier. I guess the next challenge is to see where I am with this app in 2-3 months for now and see if this habit stuck with me.
I thought I'd share because this is something that I actively wanted to solve in my life for the past 4 years but I just couldn't figure out a way to do it but it's a net positive to my life so I figured I should share.
Feel free to try it out, there's no sign ups and it's free.
Here's the link: https://apps.apple.com/us/app/reign-budget-expense-log/id6760743385
Posted Apr 2, 2026, 10:33 PM UTC