I think this is a very undervalued software product, which for unknown reasons has passed by many music bloggers on YouTube.
And those few bloggers, into whose hands Flux fell, did not understand the main advantages and the main purpose of this app.
Imagine being able to put down certain effects at a certain time throughout the entire track. Moreover, each track individually and with any effects built into this app.
That is, not to manually, randomly, press the buttons and effect controls of different plug-ins, but to program the effect of these effects with high accuracy throughout the entire musical composition, well, or in relation to a specific sample in this one.

I highly recommend it to those who want to make their compositions alive or even change them beyond recognition.
Especially well suited for tracks with percussion and rhythm sections.

It feels like this synthesizer is made by one of the world's most brilliant developers. With each update, he is getting closer and closer to the ideal. Scrupulousness and accuracy in everything, ease of use even on an iPhone. There is everything here, including a compressor and all the necessary effects that we are usually used to buying additionally, one of the best and most convenient arpeggiator, we can say that I mainly bought it because of it, but not only of course.
But the only thing is that I would like to draw the developer's attention to the fact that when used on an iPhone, it is necessary to make the response area of the squares into which the notes are placed in the arpeggiator, otherwise it is not possible to put and remove them from the first poke. Plus, for the ideal, there is not enough rollback button for at least 20 steps back, now there is none at all. Not critical, but it would be cool.
Although it is stated that the synthesizer works only as an AUv3 plugin, but as it turned out, it feels great in standalone mode. I connected a midi keyboard to the phone, and a powerful audio system via Bluetooth, launched Copperhead and everything integrated perfectly and started playing, and without any delays, just perfect!
On this synthesizer, you can wind up amazing sounds, starting from ready-made presets, which do not happen a lot. It is advisable to add new presets with each update - as a wish, although it gives great pleasure to construct different interesting sounds yourself.
In short, if someone reads these lines and thinks it's worth taking it or not - definitely worth it, especially on sale! This synth is one of the best.