Let's first define what do we mean by synchronous multi-player and asynchronous multi-player:
Synchronous multi-player game:
It can be defined as a:
multi-player game
meaning it requires >1 players for the play to be complete
that requires synchronous activity
that is, the players need to be connected together at the same time and they need to take actions in time-bound manner.
1. karaoke singing
2. timed quiz
3. rapid/speed chess
4. Battleship
It can be defined as a:
multi-player game
meaning it requires >1 players for the play to be complete
so that the players can play asynchronously
that is, the players need NOT be connected together at the same time and they can take their actions at different times independent of each other.
Given the global reach of the mobile app stores, it's very easy to get users from across the globe (in different timezones) using the app at their convenient times.
Games that want to build a combined global user-base should naturally consider an asynchronous multi-player game mechanics.
Playblazer platform is by its nature supports asynchronous game mechanics. However, if the users are online at the same time, it can very well function in synchronous mode.