Don’t give your info away to just anyone who asks.
I’m not good enough at math to keep all of my books in my head, and my handwriting is absolutely atrocious, so physical ledgers don’t really do it for me either. This is why I use certain apps and services to keep track of things like my regular expenses, credit scores, and so on. That being said, while I am a proponent of the digital age, it is absolutely mandatory to vet these apps rigorously before you input any personal financial information. Net security may be better than it was twenty years ago, but it still ain’t perfect.
Firstly, never download apps from outside approved app stores like the Apple Store or Google Play Store. If you didn’t know that was an option, good, you didn’t need to. Any apps on the official storefronts have to go through at least a basic vetting process before being listed, so keeping your downloads there exclusively will weed out any overtly malicious programs. Even among officially sanctioned apps, however, there are some bad actors slipping through the cracks. Before downloading any apps, make sure to read its user reviews and do some basic Googling. If there are any obvious problems or controversies, you’ll find it.
Secondly, verify the app’s security measures. Ideally, you want this to be something you can’t use just by opening it up. You want, at the bare minimum, an account and password lock and two-step verification. Depending on the nature of the app, you should also check to see if the company that owns it offers any kind of insurance. For example, most banking apps are covered by the Federal Deposit Insurance Corporation, which ensures up to $250,000 of your money is reimbursed to you in the event of some kind of major bank failure.
If all the security is in place and the feedback is good, then you can start using that app. Remember, as helpful as apps can be, you still need to keep a watchful eye over your finances.