Question about GPLv3 license

[Amanda Madison]

Hi everyone,

We plan to use the GNU STL library that has the  GPLv3 license with
the addition under section7 (full license:
https://gcc.gnu.org/onlinedocs/libstdc++/manual/license.html) as a dynamic
library as part of our Android software. We have some questions

1) Does that mean that I have to publish the source code of my software? or this
fall as part of the exception?

2) We plan to use it commercially, do we have any restrictions in the contract?

3) In the software that we redistribute, do we have to mention anything related
to the GPLv3 license?

Any help with any of these questions is greatly appreciated.

Thanks,
Amanda.