As the name suggests "Interest calculator" will calculate the interest in just one click. Also this app will calculate the complex compound interest specially if you want to calculate compound interest in which you are depositing a particular amount at particular intervals.(Like SIP).
This interest calculator app has very customizable features. You can set interest format, calendar type, date format etc. you can see these features in setting menu.
Also this app has only bottom banner ads. Its doesn't use full page annoying ads like other apps.