A flight review must be done every 24 months before you can act as PIC using your FAA certificates unless:
1. You are employed by a US airline certified under Part 121 or 135 or a rated pilot in the US military. The airline's / military's proficiency checks take the place of the required flight review. or
2. Get a new rating on your certificate. For example, if you add an instrument rating to your PPL, the 24 months starts from your instrument checkride.
There are a few other exceptions provided but the 2 above are the most common.
These checks can be done anywhere in the world and in any aircraft; however, it must be done by an FAA certified instructor or examiner.
The date of your last flight has no affect on your Flight Review's currency. If it was 24 month's since your last flight review and you have flown as PIC every day since then, you are not legal to fly tomorrow as PIC until a flight review is conducted.