I’ve used a number of different ear training apps, including Justin’s own ‘Ear Trainer’, but I’ve now stopped using them entirely and instead just transcribe real songs. I spend at least 5 minutes (often longer) on a ‘song of the day’, either a melody/riff/lick or a chord progression. It’s a rather different experience as you have to deal with less than perfect audio that is often cluttered with drums/bass/vocals etc. You don’t get much practice at the more obscure intervals, but it’s a ‘real world’ exercise, and there’s a side benefit of learning licks and ideas too.
I can see pros and cons to both, but this is the path I’ve chosen.
Whichever way you go, ear training is really valuable and can only make you a better musician.
I use both Justin’s Ear Training App and free app that I got called Perfect Ear. I use them on different devices. @mathsjunky I have just made space in my practice routine for Transcribing stuff and am now doing 10 minutes a session on this. I am finding it challenging but believe that you are right about being a better musician through learning all this stuff by ear. . .Would be great to get to the point where I need to learn from writtin songs less and less. . . time will tell if I get there.
I think the ear training stuff is valuable no matter how you approach it. Use the app to learn the sound of the intervals (both ascending and descending!!) and transcribe to get the feel of them in chord progressions and songs. . . I think the two activities are totally complementary and when coupled with some theory study super powerful. . .
I suggest you check out Perfect Ear if you’re in the market (it has a free version) . .it works on both IOS and Android though originally it was an android app and has somewhat less features on the IOS version at the moment.