How can I log simulator time in ForeFlight Logbook?

If you log Approaches or Holds in a Full Flight Simulator (FFS) or Flight Training Device (FTD) you can set the Category/Class to the simulated version of the aircraft and your currency will reflect accurately. However, if you log Approaches or Holds in an Aviation Training Device (ATD) it will not because that currency is based on a 2 month cycle.