ActionTiles is only compatible with Device Type Handlers that include claims Capability "Sensor" and/or "Actuator" (or, as of ActionTiles v6.4: Switch, Battery, or Temperature).
This means that even if the Thing claims a Capability that ActionTiles supports (full list coming; but there's a lot, obviously: Switch, Temperature Sensor, Contact Sensor, Garage Door, ...), you cannot add it from your SmartThings Location if it is missing the "base" Capabilities that every device is supposed to have.
99% of SmartThings's officially supported "Works With SmartThings™" devices are correctly coded. If your Thing is missing, you are most likely using a Community developed "custom device type handler".
You or the developer of the DTH need to at least one these lines to the custom DTH code:
capability "Sensor" capability "Actuator"
As of ActionTiles v6.10, any of the following are also detected by the Authorization process:
capability "Switch" capability "Battery" capability "Temperature" capability "Refresh"
If a device with stock Device Type Handler (i.e., a "Works with SmartThings"™ certified device) does not appear in device authorization list, please contact ActionTiles Support, giving the exact brand/model of the Thing. Devices with known issues will be likely be already discussed in our Support Forum.
Only devices that are officially supported by SmartThings are officially supported by ActionTiles.
Customer support service by UserEcho