I'm going to second the recommendation to find a simpler ear training app. Recognizing chords regardless of inversion and in random order is fairly advanced. Regardless...
Ear training took a while for me to get the hang of.
What my Aural Skills professor taught me was a simple way to train for chord identification, though keep in mind, just like any skill it takes regular practice.
First, begin with tonicization if possible within the app you use.
I highly recommend learning solfege for this. If you don't already know solfege or can't dictate melodies, work on that first. Chords are far more advanced.
At the beginning of a piece I want to notate chords for, I use the pattern
Do-Mi-Sol-La-Sol-Fa-Re-Ti-Do
for major keys.
When a chord is being played, try to match (singing or playing) the solfege pattern of chords to whatever chord is being played. The tonic, for example, is Do-Mi-Sol.
Memorizing the solfege for each chord is incredibly beneficial.
It is also imprtant to note that for Ear Training, most chords are played in inversions that lend to being played simply on a keyboard.
Here's a "chart" to help.
I: Do-Mi-Sol
ii: Re-Fa-La
iii: Mi-Sol-Ti
IV: Fa-La-Do
V: Sol-Ti-Re
vi: La-Do-Mi
vii°: Ti-Re-Fa
And that will bring us back to
Do-Mi-Sol ;)
While certainly more complex than simply learning to recognize chords on their own, this method is far more comprehensive and prevents hiccups such as not being able to differentiate minor chords.
I hope this can be of use for somebody!