Great Idea & App
But Just A Suggestion.
Don’t you think that people will really prefer to download it just to know Simple interest?
However they can use Simple this formula
I = P✕R✕N and then divide it by 100 in their calculator
Another Suggestion.
If you could add some more function or feature like
Compound Interest
Annuity
Perpetual Interest
or More In One App . It will attract user more
Currently App Development Competition is so High! If you need to earning app development side then It’s Very important to published your app in the Playstore!