Describe an app you find useful

The app I probably rely on most is a fairly basic budgeting one, nothing flashy, that I started using about three years ago after a friend, slightly exasperated with me, more or less installed it on my phone during a conversation about how I never seemed to know where my money went each month. I use it for logging pretty much every purchase, no matter how small, which sounded tedious when she first suggested it and genuinely was tedious for the first couple of weeks, until it turned into enough of a habit that I barely notice doing it now, usually right there at the till before I've even left the shop. What makes it useful to me isn't really the categorising or the little charts it generates, though those are a nice touch — it's that it removed the vague anxiety I used to have about money, which came less from actually having too little and more from simply not knowing the numbers at all. Not knowing, it turns out, was doing more damage to my peace of mind than the numbers themselves ever would have, once I actually looked at them properly. I've recommended it to at least three other people since, with roughly the same slightly forceful approach my friend used on me, which feels a bit like paying the favour forward, if that doesn't sound too dramatic for something as mundane as an expense tracker.