It is for free with no ads and well worth checking out as it is one of the more complete apps for Android when it comes to music making.
I am mentioning it again as it had a small update and I am happy to see that it is getting some attention still from the developer.
If you are used to for example Caustic my guess is that you would not change to vuKNOB but it is well worth to have in either case as it has a brilliant and very fun arpeggiator that can use any scale and very easy to change in X-Y pad style. Plus direct recording built in to export later.
Thee same developer also have another app that makes it possible to connect other devices together for jamming with other people over wifi.
P.S as the project is open source (C or C++) and the developer want other people to be involved as well.
If interested go here:
https://www.vuknob.com/
Google Play info:
https://play.google.com/store/apps/details?id=com.holidaystudios.satan
vuKNOB is a fully fledged musical sequencer studio for your smartphone, or tablet device! Designed for Expert Knob Twiddlers and Inspired by sound trackers of the past, vuKNOB takes music production in to the portable future.
- Select from a large number of machines for generating sounds and effects
- Load WAV sample files
- Low latency support ***
- Export sequence to MIDI
- Export to OGG (Requires NEON enabled CPU)
- Share your music through for example Soundcloud!
- Live arpeggio
- Pitch bend using accelerometer
- Twiddle with knobs on the go!
- Multiple users using companion app vuKNOBnet! Twiddle the knobs with your friends!
Machines include classics like the silverbox, and the DX7 FM Synthesizer! It also includes effects like reverb, compressor, delay, flanger, low pass filters, high pass filters, stereo separation and vocoder.
*** Low latency support is only available on devices that has implemented Googles low latency drivers, or devices supporting the Samsung Professional Audio API. Confirmed working are the latest Nexus series devices and Samsung Galaxy S6.