Tasker is a general purpose automation app for Android. It costs a few dollars and takes a bit of time to learn, but once you learn the basics it is quite useful. In this post, I briefly describe how Tasker works, then list simple things I've implemented in Tasker, and lastly describe what things in general Tasker can be useful for.

Tasker basics

The core functionality of the app is a trigger-action principle. Tasker lets you select from a wide variety of triggers (Tasker uses the word "profile") -- for example, connecting to a specific bluetooth device or it being a certain time of day. And it lets you execute a wide variety of actions -- for example, changing device volume, brightness, or more complicated things like launching apps. Then you can tell Tasker to execute one or more actions when a trigger starts/stops happening.

Two additional features which give this trigger-action paradigm more functionality are Tasker's GUI builder (Tasker uses the word "scene") and variables. The GUI builder allows you to make custom graphics appear on your phone -- for example, you can create custom buttons or dashboards. Variables are useful for storing data -- for example, you can store the SSID of your current internet connection. Tasker also lets you store lists of variables ("arrays"). 

Tasker can also do things beyond the reach of your phone. For example, with some effort, you can configure Tasker to push any data you want to a google sheet. 

Simple tasks I use Tasker for

Here is a list of very simple things I've implemented in Tasker, and how they help me.

1. If my phone connects to my bluetooth headphones: open Spotify and set the volume to a good value. The "open Spotify" part is useful on the go. The "setting the volume to a good value" helps me avoid damaging my ears if the volume was accidentally left on high.
2. If my phone is flipped over, mute the media volume. If it's flipped again, restore the previous volume. I've been using this to avoid watching and listening to YouTube ads. If I click a video and an ad starts playing, I simply flip my phone, wait a while, then flip it back. So much nicer than fiddling with the volume slider to try to mute the ad.
3. Set phone brightness to high in the morning. Set it to low in the evening. Good for not blinding myself in the night / not being able to see my screen in the morning.
4. Turn off haptic feedback at night. Useful for not disturbing roommates. This setting was super annoying to change manually.

Overall, I would describe these as slight time and sanity savers -- nothing lifechanging, but I'm glad I have them.

There is an extensive list of example use cases here: https://tasker.joaoapps.com/exampleuses.html I don't find them particularly compelling but they do give you an idea of some things Tasker is capable of.

Who is Tasker for

Reasons you might want to use Tasker

1. There is a repetitive task you perform on your phone that you wish you could automate away.
2. You have specific visions for unusual things you want your phone to do automatically, which other apps do not address. (For example, you want to implement a very specific custom dashboard on your phone.) 
3. You are a "Linux user type person" who enjoys implementing things for yourself.
4. You are willing to put in time to learn Tasker's terrible user interface. 

Reasons you might not want to use Tasker

1. You don't have an Android phone, or you can't think of phone tasks that you would want to be automated. 
2. The stuff you want automated is closely approximated by existing apps. Or you might prefer IFTTT, another automation app. 

How to get started with Tasker

I recommend downloading the app and ignoring the tutorial. Just mess around with the "profiles" (triggers) and "actions" until you get the hang of it. Then you can start Googling how to incorporate scenes, variables, and more advanced features.