This sounds great. I would definitely love a splitwise alternative in particular!
You may want to think about using another name for your app suite though. Since it may bring confusion with the simple mobile tools (https://simplemobiletools.com/index.html) which for example also have a “Simple Notes” app.
Did you really think that people wouldn’t realize that you copied the other comment? Of course you’ll be down voted.
Phone screen pixel density actually went down in the last 10 years due to bigger screens.
It may become complicated if some day she does fall in love and if it’s with someone else. She may be faced with hard choices if this happens.
Because it hurts less when you hit your foot against it when going to the toilet during the night