Mobile apps have changed this paradigm. Ease of use now trumps functionality in driving new users to adopt apps. The most popular apps are often breathtakingly simple.
You only get one shot at a first impression with your app, so try and resist loading it down with too many features. Hold back and add some later as you track the usage behavior of your users. You will get more credit for adding or changing the app later than for guessing wrong out of the gate.
If the scope of what you are trying to do with your app defies simplification, one approach is to split the functionality into two or more apps, striving to make each one as simple as you can.
People don't read docs to learn apps. If your app requires users to attend training or read documentation, you may want to go back to the drawing board.
Perhaps less is more when it comes to blogs as well, so I will leave it at that.