The subscription is a one-time payment, done by purchasing the paid app.
Moreover, when you change your phone(Android → Android or iPhone → iPhone), there's no need of repurchasing.
You may download Money Manager using the account that you made the purchase with, whenever, wherever you wish to, as long as you stay on the same platform.
However,
since Google Play Store and App Store are two different operating systems, it is inevitable to repurchase the membership when switching platforms.
The reason we are running separate services in two different systems
is to ensure the stability of our service in order to provide you with maximum efficiency upon using our service.
We kindly ask for your understanding in this matter.