It is certainly possible to use Audit Assistant in other countries. It is currently hosted from NZ, however the internet speed is sufficient to work well (we have users in the Pacific Islands and Australia).
Regarding IFRS and ISA, we currently reference to the NZ equivalents for NZ firms (XRB), AUASB for Australian equivalents, and IFAC for the rest of the world. The audit processes are the same, so anywhere in the world using versions of International standards will work - but of course the final responsibility for knowing and complying with your own local standards remains with the Auditor.
Our Thomson Reuters/Brookers financial reporting template checklists are based around the NZ standards only at this stage.