Google Play have set edjing PRO for 0.10€ for some days. Do not know if this offer extends over the whole world...

Google Play:
edjing PRO

Think it was about a year ago that Native Instruments started to release songs as "stems" for DJ's to have more in-depth control over their sets by having the main parts separated into different tracks, making a lot of more creative decisions possible.
Now there is this application that can play stems...

Google Play info:
Stem Player
​and more information regarding Stems:
http://www.stems-music.com/

About the Stem format:
As an open multi-track audio format, Stems enhances creative possibilities for DJs, producers, and live performers. A Stem file contains a track split into four musical elements: a drums stem, a bassline stem, a melody stem and a vocal stem for example.
The Stem format provides the ability to freely interact with a track's different musical elements. Each stem can be controlled independently to create instant new mixes, mashups, instrumentals, acappellas and more.

So edjing is now edjing Mix with some new improvements. and integration with the hardware mixfader that the same company makes.

Google Play info:

Introducing edjing Mix - the brand new version of the world's most downloaded DJ app voted Best App by Google 3 years in a row (2013-2014-2015) - reworked to ensure even greater performance level.
Designed in partnership with pro DJs, edjing Mix transforms your device into a real DJ setup and stretches the limits of djing on mobile, offering unlimited creative freedom.Need to put down a set out of nowhere? To enliven your next party? To rock out an unplanned jam?
edjing Mix offers all the essential DJ tools to create amazing mixes on the go.
Access millions of tracks coming from Deezer, SoundCloud and all your local folders and remix in an instant with more than 20 DJ fx and features. Not to mention the all-new sampler and the hardware integration to push even further the boundaries of the mobile djing.
* ‘edjing Mix offers the same capability of a pro DJ software except with the convenience of being on a device that fits in a pocket.’ DJ Tech Tools
* 'The only application to offer real time sound processing, edjing shows you how it feels to be a real DJ' GQ
Remix +50 million tracks
- Music library (access to all your local music)
- Soundcloud integration
- Deezer integration (requires a Premium account)
- create multisource playlists with songs from both your local and streaming sources
- smart search feature that displays results for all your music sources on the same screen
- queue system to prepare the upcoming songs
- advanced sorting: browse by alphabetical order, BPM, or Time
A new major feature: the sampler
- access 16 free samples to trigger when you want on top of your music: siren, gunshot, kick, snare...
- possibility to link the sampler to the crossfader to cut the pads' samples sound depending on your crossfader's position.
- upcoming new samples created by Pro DJs
All the must-have DJ tools
- automatic BPM (Beats per minute) detection for all your songs
- Tap BPM feature to manually adjust the BPM of your tracks
- continuous sync between your two tracks
- a little audio spectrum to navigate in your music
- a wide audio spectrum for optimised beats detection
- pro audio FX: Echo, Flanger, Reverse, Filter
- audio FX expansion (in-app purchase): Roll, Roll Filter, Steel, Gate, Double Beats, Phaser, Color Noise, Beatgrid, Band pass, Band stop, Reverb, Reverse
- automated audio FX sync on the beats (loop, cue, seek)
- loops: from 1/4 to 8, or customizable through 'in' and 'out' point
- set up to 4 Hot Cues on each deck
- EQ three bands and Gain
- Pre-cueing with headphones (in-app purchase)
- Automix mode to let edjing mix and do seamless transitions between your tracks
- ultra precise scratch
- a ""Slip"" mode that can be activated for Loops and Scratch
- HD recording of your mixes and scratch routines in .wav format
- 4 skins to customize your turntables (in-app purchase): Diamond, Gold, Neon, Metal
Turntables designed by pro DJs
- intuitive interface that gives you a direct and quick access to all the essential features to gain time during remix live sessions
- optimized turntables: you are only 1 click away from the essentials
- possibility to reorder the audio FX lists to customize the panel
Compatible with Mixfader
- remix with edjing Mix and the world's first wireless crossfader (themixfader.com)
- Mixfader becomes your crossfader for you to scratch on edjing
""To detect and connect to your Mixfader, the app needs permission to activate your Bluetooth, and access your location. This is required by the Android Bluetooth System.
Mixfader requires Bluetooth LE and Android 4.3 onwards.""
Remix from songs your Android Wear
- access your set key information
- sync your songs
- manage 4 DJ effects

WHAT'S NEW
Thanks for using edjing Mix! This version includes:
- new feature: you can now link the sampler to the crossfader (to cut the pads' sound depending on your crossfader's position)
- improvement: new audio FX look and feel
- fixed bug on the sampler
If you enjoy the app, please take a moment to rate it on the store, it is really helpful for us :)
Thanks in advance!

Mostly regarding Android M...

Google Play info:

- Improve sync with keylock
- Full compatibility with devices running Android M.
- MIDI control is now compatible with Android M.
- Cross DJ 3.0 for Android supports multichannel audio on devices running Android Marshmallow.
- Design improvement: a scroll bar has been added to the library, making navigation through the songs much easier.
- Many bug fixes.

FULL VERSION, ALL FX INCLUDED - NO ADDITIONAL PURCHASES, NO POP-UPS

"Cool piece of work." (DJ Mag)
"An impressive app." (The Guardian)
“Challenging our notions of what can be done on a touchscreen.” (Android Police)
"Good looks, great sounding FX, great sync engine, ‘slip’ mode, proper loops and cues." (DJ TechTools)

/// MIX IN PERFECT SYNC
• Accurate BPM detection of your music, down to the last decimal
• Stable sync: one-press, and the 2 tracks never go out of phase
• Progressive, manual pitch bend
• Customizable, manual pitch range (4, 8, 16, 32, 100%)
• Beatmatcher: parallel waveforms to visually check if your tracks are synced
• Accurate beat-grid editing: make any track sync properly
• Quantize: hot cues and loops are automatically set on the beat
• Smart-seek: tap on the waveform to fast-forward & get a seamless jump
• Split Mono: pre-listen your music tracks before mixing them
• Automix: let Cross DJ mix your tracks and play music automatically, from any sources (playlist, album, etc.)
• External mixer: control EQs and crossfader with hardware mixers

/// OUTSTANDING AUDIO PERFORMANCE
• Low latency: music reacts instantly to your actions
• Extremely realistic scratch sound as on real turntables
• Record your mixes live and in high-quality
• Autogain: automatically equalizes the levels of 2 tracks
• Keylock mode: change BPM without affecting the tone
• Key detection: detect the key of the songs and know which tracks sound good together
• Supported MIDI controllers: U-Mix Control Pro 1&2, Pioneer DDJ-SB, DDJ-WeGO2, DDJ-WeGO3

/// INTUITIVE INTERFACE
• 2 turntables, 3-band EQ mixer - with DJM EQ preset
• Sampler: 72 samples + 12 exclusive loop samples, synced to the main player
• Record & play your own samples
• XY effect pad, 16 hot-cues pads
• Large buttons, optimized for small screens
• Mix SoundCloud: explore, play and mix all SoundCloud
• Big waveform view: scratch & see the music + set cue accurately
• Music player compatible with MP3s, AAC, FLAC and more
• Sort your music library by title, artist, album, BPM or length
• Navigation by folder
• Separate tabs: swipe to display different panels on each side
• Portrait mode: big single player
• Change each deck’s color: blue, orange, red, yellow, green, purple, pink
• Optimized for mobile & tablet
• Optimized for Intel processors

/// MINIMUM CONFIGURATION REQUIRED
• Android 4.1
• 4" screen
• RAM: 1GB 
• Dual-core processor

/// WATCH CROSS DJ PERFORMING
Mix with an external mixer: http://youtu.be/oZnSzX_UnkE
Pioneer DDJ-SB: https://youtu.be/XRAao2CFfQc
Pioneer DDJ-WeGO2: https://youtu.be/KRP_Cy3jQM4
MIDI control: https://youtu.be/5ocke5GDg78
Mixcloud integration: https://youtu.be/pzKrExmY2Po
Street DJing: https://youtu.be/q2nokB3qxPU
User videos: https://www.youtube.com/playlist?list=PLj1938JIqZA4VjrPLgvJtiLFyFIvwaw6H

/// FOLLOW MIXVIBES
YouTube: www.youtube.com/mixvibes
Google+: https://plus.google.com/+mixvibes
Facebook: www.facebook.com/mixvibes

So this was funded far over their Kickstarter goal and does look like a solid piece of hardware after seeing the videos of people using it in action.
If being a DJ it will be hard to find something this portable and useful. 
I Like that there is no need for cables either for electricity (ten hours autonomy) and for connecting to devices as the connections go through Bluetooth. 
Will also work for windows so it is not tied down to Android/iOS. 
Think that it is good that they did not opt for making it work only on the edjing DJ application which the same company developed but will work with other DJ apps as well.
To read more or to pre-order the mixfader 30 % off go here:
mixfader pre-order

P.S- The possibility to pre-order will last throughout the summer.

Seems to be a must if being a DJ and using Traktor.

Play Store Info:

TKFX is a dedicated Traktor Pro Effects controller that features an X/Y pad. TKFX allows you to use Traktor effects in a completely new way. Select the effect you want to use, assign effect parameters to X/Y and Z axis, enabled the effect in the wished deck and touch the pad. The effect is automatically applied.TKFX is completely plug and play which means that you don’t need to waste countless hours in MIDI mapping. TKFX knows all about TRAKTOR PRO effects, just select the effect you want and all it’s parameters and functions will be automatically reflected on the respective buttons. TKFX supports effect unit operation in single or group mode.

Key features:

- X/Y pad
- Plug & Play
- Hold function
- BPM sync
- 4 effect units
- 4 memory banks
- Single or group mode
- Wireless or wired connection

In version 2.0 we have redesigned the app from the ground up to allow even more possibilities:

- Multi effect mode
- Assign multiple parameters to a single axis, including amount and on
- Link mode (to trigger four units at the same time with a single pad)
- USB wired connection
- Phone devices support

For detailed documentation please visit www.imaginando.pt

PRESS REVIEWS:

"TKFX is excellent fun to use and DJ effects respond especially well to this kind of real-time effect control." - Hollin Jones - AskAudio Magazine

"But wouldn’t it be nice to use a tablet for X/Y control of effects? TKFX does that, and nothing else – but it does it damned well." - Peter Kirn - Create Digital Music

"I recommend this app for anyone who likes to use the effects inside of Traktor, as it offers you an instant way to add and manipulate effects with ease" Alan Churchill - Traktor Tips

"In conjunction with a dedicated hardware controller, TKFX is a simple but effective solution for extended Traktor FX control." - Declan McGlynn - Resident Advisor

This does look like a simple but well crafted hardware and think that if there is any DJ's or dabblers in the art go to the Kickstarter page and check it out in more detail.
It will work ford Android of course as otherwise it would not be mentioned.
It is well over the goal so it will be made and there is also some early bird offers left where it is possible to get it 40 euros cheaper at 69€
Kickstarter page:
https://www.kickstarter.com/projects/396428272/mixfader-the-worlds-1-connected-object-for-becomin

So to read the review of the knobs that stick directly to your device for some controller action go here:
http://www.digitaldjtips.com/2015/04/review-tuna-knobs/

Play Store info:
Ready to rock your next party? Introducing djay 2 - the next generation of the world's best-selling DJ app is now available on Android.djay transforms your Android device into a full–featured DJ system. Seamlessly integrated with Spotify and all the music on your device, djay gives you direct access to mix your favorite songs and playlists instantly. You can perform live, record mixes on–the–go, or enable Automix mode to let djay create a seamless mix for you automatically. Whether you are a professional DJ or a beginner who just loves to play with music, djay offers you the most intuitive yet powerful DJ experience on an Android device.

FEATURE HIGHLIGHTS

• Spotify integration 
• Music library integration (all files on your device, no access to Google Play Music)
• Automix 
• Match: intelligent song recommendation engine powered by The Echo Nest
• Audio FX: Flanger, Phaser, Echo, Gate, Bit Crusher 
• Mixer, Tempo, Pitch-Bend, Filter and EQ controls 
• Looping & Cue Points 
• Colored HD Waveforms™ 
• Live Recording (local music only)
• Sampler with included sound FX, drums, and an exclusive pack by Snoop Dogg
• Single Deck portrait mode 
• Pre-Cueing with headphones (using Griffin DJ Cable) 
• Advanced time-stretching (requires quad-core Nexus device) 
• Automatic beat & tempo detection 
• Auto-Gain 
• Support for all major audio formats 
• Support for Bluetooth devices
• Support for DJ MIDI Controller (Reloop Beatpad)

Watch DMC Champion DJ Rasp perform on djay for Android: 
http://youtu.be/OhBJnDUxMEU

Spotify integration requires Spotify Premium and an internet connection, a FREE trial is available.