FL Studio (a.k.a. Fruity Loops) released for Android
This looks surprisingly good for an Android app, but I think you need to be running Jelly Bean to avoid latency-related issues.
Website / Google Play Store
Professional and amateur music producers have created thousands of songs using the FL Studio sequencer, formerly known as Fruity Loops, and those beat makers can now create or finish projects on their Android devices. Image Line has released a mobile version of FL Studio that supports multi-track editing that can then be opened in the desktop version. The app features drum pads, instruments and extensions compatible across devices, virtual piano keyboard, synthesizers, and a number of effects.
FL Studio has a long list of features, but the app may be challenging for some devices. Android 2.3.3 or later is required to use FL Studio, and phones or tablets will be compatible thanks to optimizations for 1280x800, 800x480, 960x640 and 480x320 screens. Audio latency may be an issue on some devices, so hardware capabilities will affect timing and quality. The number of included audio files and diverse capabilities of the app leads to more than 209 MB of data being used.
FL Studio is available now for £12.95 / $19.99. Some FL Studio features available in the iOS version of the app are not yet available. Image Line plans to bring feature parity in the future by supporting wave editors, custom samples, .instr file loading, background audio, SoundCloud uploads, and in-app shopping. For now, users will have to settle for the features listed here