The calculator is offered "as is". There are no guarantees of precision, exactness, or aplicability to any given purpose. The developer has no responsability for any damages incurring from usage of this software. Always double-check results against other sources if you are going to take some actual financial decision!
The ad-supported flavors of this app collect and transmit the Advertising ID, exclusively for advertising and analytics purposes.
Apart from that, this app does not send any other user data to any remote party, and no data is shared with other apps.
When the user saves copies of the memory, they are written as files in the "storage area". Files in this area can be manipulated by any other app installed on the same phone. If this is a problem, remove these files from the SD Card once they fulfill their intended usage.