If you have an iPhone or an iPad and play guitar no doubt you will have thought about the possibilities of using it as your practice amp and there are a few Apps available now that will let you do just that. The latest to come storming onto the scene is JamUp Pro from Positive Grid. Now cleverly these guys have also created a very sleek and compact interface so that you can easily plug your guitar and headphones in called the JamUp Plug, you can buy this via Amazon for $19.99. By the way it is possible to run a cable from the headphone jack into your audio interface and record your guitar into whatever DAW you use on your computer too as an added bonus.
The App is very simple to use as you can see in my demo you have a presets section which is a great place to start, load up each preset by tapping the name and have a quick play then start editing presets you like to get more of an in-depth knowledge of the power of this software. By double tapping on any part of the signal chain you are given the other available options, for example by double tapping on the Amp you will see the a scrolling list of available amps to switch out and some that are locked available in their store. Once you have chosen an amp, you can edit your settings and move on to the next part of the chain, single tap to bring up the edit view for each pedal and click the LED to turn it on or off. You can easily move the order of your effects and amp by holding and dragging each item which enables you to experiment with say Modulation effects in front of the amp or after.
The amps that have been included are all household names so you immediately have a selection of clean, crunchy, high gain and metal amps to choose from but you do also have the option of buying some additional amps in the Positive Grid store and also more effects and there are bundles available to save you a few dollars too. There is a free version of the software available in the iTunes App Store called JamUp Lite which includes 1 amp and 4 effects, you will need an interface to plug your guitar into your iPhone/iPad though.
Check out http://www.positivegrid.com/ for a complete run down of features including the Phrase Sampler and Jam Player