We've had some cracking App Of The Days previously on Pocket-lint, but this is surely one of the best as it brings the power of a multi-effects processor to guitarists everywhere.
Not only this, but the free version has been available for around a month now, meaning Guitar nirvana was never so cost effective. Say hello to AmpliTube.
You'll need to invest in the Amplitube iRig interface adapter - and preferably have a guitar to hand - but once kitted out you'll be able to have some very comprehensive mobile FX for both a guitar and bass.
Using a plethora of amps, stomps, cabinets and mics combined into a rig, this app should allow you to fully customise your setup and create the precise sound you want. The interface looks stunning and everything seems to be in the right place, with all the knobs and dials you could ever want. And it doesn't sound bad either.
In the package you'll get 3 stompboxes - including delay, noise filter and distortion - and this can be added to through downloadable content up to 11 stops and 5 amps plus speaker cabinets.
All of this can be controlled via the app and makes for a pretty favourable alternative to a full music rig. You get 36 presets, which can be saved down and you can import and play along with your own songs all with real-time effects.