StepBud is a MIDI Sequencer with Audio Unit AUv3 plugin, Audiobus and Ableton Link.

Add an unlimited number of steps to your sequencer.
Your steps appear with a LED and a fader on top of your screen.
You can change the active mode that your step faders displaying/controlling.
- Set the current note or chord in range of the scale and key you selected with respect the range of the octave you want to focus,
- Set the velocity, rate, gate time, modulation, pitch bend, portamento, probability and swing for each step,
- Try increasing the rate and repeat count your steps if you want to add more flavor.
- Send unlimited custom MIDI CC messages if you want to control your hardware or software synth parameters.
- Lock steps if you don't want them to change their value.
- Skip steps for creating interesting live performances.

Below the step faders, you have a master fader where you can control your entire sequencer. It has two modes which you can change from the settings strip on the bottom of the app.
- In copy mode, it assigns its value to each step.
- In shift mode, it shifts up or down each step.

If you want to go off-scale or try some crazy chords on some of your steps, or maybe on all of them, you can go to the Step Editor by double tapping the LED of the step you want to edit.

In StepBud's powerful Step Editor, you can set your step's notes either from the virtual keyboard or your connected MIDI keyboard. Don't forget to enable MIDI in port of your MIDI keyboard or the you want to receive MIDI from the settings menu. You may also preview the selected notes by pressing the preview button in Step Editor for making sure you created the perfect sound for your particular step.

You can also toggle the steps you want to disable by tapping its LED.
If you long-press the LED, you can access a menu where you may copy/paste the steps around, remove them or edit them.

If you enable the lock mode from the settings strip on the bottom of the app, you may adjust each visible step fader on the screen by a single swipe gesture without having to lift your finger up.

Try to change your arppegio mode from the settings strip. You can sequence your steps up, down, up-down or random order.

StepBud is a MIDI sequencer app and it does not generate sounds itself. You need to route its MIDI out port in the settings menu to the audio app you want to sequence.

Please note that you need to have an iOS 11+ device and an Audio Unit host application such as AUM, apeMatrix, Cubasis, BeatMaker or Audiobus in order to use the StepBud as an Audio Unit plugin. And don't forget to route StepBud's MIDI out to the app or audio unit you want to sequence.

StepBud's MIDI layer powered by free and open-source project AudioKit
https://github.com/AudioKit/AudioKit

Also, StepBud offers its core components for free on GitHub. Feel free to star, fork or contribute.
https://github.com/cemolcay/MusicTheory
https://github.com/cemolcay/LiveFader
https://github.com/cemolcay/MIDIEventKit