Rozeta Sequencer Suite is described as 'Rozeta is a suite of MIDI sequencers and controllers that lets you explore a new, freeform approach to sequencing and controlling mobile music apps' and is an app in the Audio & Music category. There are four alternatives to Rozeta Sequencer Suite for iPad and iPhone. The best alternative is Ribn. It's not free, so if you're looking for a free alternative, you could try Knob Lab. Other great apps like Rozeta Sequencer Suite are Mozaic Plugin Engine (Paid) and Midi Studio (Paid).
Ribn is a MIDI controller with 8 assignable ribbons. What makes Ribn unique is its ability to record and loop your finger movement. This allows you to add organic repeating modulation to your synths and effects, kind of like complex LFOs.
Mozaic runs inside your favorite AU MIDI host, and gives you practical building blocks such as LFOs, pre-fab GUI layouts, musical scales, AUv3 support (with AU Parameters, transport events, tempo syncing, etc.), random generators and a super-simple yet powerful script language.