Trigger makes a space for itself by being more friendly and more restrained in the way that it does things. By default the free version of the app allows you to initiate actions based on Wifi, Bluetooth and NFC triggers. For some users that will cover all that they need.
However if you do need more control an upgrade to the Pro version adds a number of other trigger criteria, for example battery, time, calendar events and even geofencing. There's also support for plug-ins, allowing you to do things like automatically place a call or send an SMS based on a trigger.
If you're planning on using NFC to automate your phone there's even a plug-in that will allow the re-use of existing tags, meaning that for a lot of activity theres not even a need to buy yourself writeable tags.
So how difficult is Trigger to use? It's pretty straightforward actually. When you launch the app you're presented with a list of your current tasks. Click the '+' at the top of the screen and you're presented with the trigger screen. You can use multiple triggers to initiate a task. Click the '+' and add those triggers that you want to use. For triggers that need some more information you are asked to select it from a drop down list. For example if you're using a Wifi network as a trigger, you will choose the network name and whether the trigger should fire on a disconnect or a connect. You can also restrict when the trigger is activated based on things like time, day, charge status, Wifi or Bluetooth status.
Once you've configured your triggers you go through to choose one or more actions. The process is as straightforward as the trigger configuration. Choose the activity, add any required information and repeat until you're complete.
I have a number of tasks configured. When my phone connects to the Bluetooth in my car Trigger disables my screen timeout, launches Xbox Music and turns on driving mode so that my texts and emails are read to me. When I leave the car it performs a reverse task. When I get home and my phone connects to my Wifi it disables mobile data and does the reverse when I leave.
I've only scratched the functionality of Trigger so far, but I'm pleased with what I've been able to achieve. More importantly it has been 100% reliable. I've never had a task fail to run, important if you're giving over an element of control to the application.
If you want to make your smartphone smarter then you should definitely get hold of Trigger.