Many are waiting for a Synthesizer for iOS that has been long been announced, SynthMaster One for iPad. Today, the developers released a preview photo of the interface as well as announced that they will present the iOS version on the NAMM 2018. Of course, Synth Anatomy will report in written and video form on this news from the NAMM. A little more patience but I think it will pay off.
More information here: SynthMaster One