Hello there. While there is a hot debate regarding the Tube VS Solid State amps (as usual!) I thought about writing a little review about the Amplitube, Ampkit and GK software for iPhone/ iPod Touch/ iPad. I own and use all the 3 programs, and I use the paid versions. A few words about this kind of software. Many consider these applications as garbage, waste of time, useless etc. Form what I can say, these applications are simply revolutionary and amazing. Yes yes, they will never replace a SVT CL all tube head standing on a 8x10 cab or a nice SS amp such as the GK RB700ii pushing a 4x10 cab. But these apps never intended to do that. These apps are intended to be used when one must use headphones or when one have no access to an amp or a bass combo. I've at home an Ibanez 20w bass combo, a sansamp PBDR, a sansamp Oxford pedal, an EBS multicomp, Bad Monkey, zoom 506 (used as tuner) and a Grombass fuzz/ distortion pedal. I also have a Line6 Bass Pod XT pro. But even the 20w combo is too load sometimes for practicing home. Furthermore it is nice to have a pocket-amp to use while I'm traveling, playing in the hotel room, train etc. As I had a iPod Touch from before I decided to buy the Amplitube and later the Ampkit (pluss the iRig interface) as these apps are ridiculously cheap. I found these apps great for use from the first time. My Vox ampplug did not match the sound or the other options these apps had. Now, as my iPod is a 2gen one (rather slow CPU) I had some issues to use the built-inn play-along options both apps had. There also some gain issues/ noise, but still, I thought that the concept was promising. The sound of the SVT amp in the Amplitube was almost as good as the SVT in the Line6, but the interface was way better. Later I bought an iPad, and man, these apps with the iPad rocks. Larger screen, more CPU power etc resulted to very good performance, good sound with very little noise. I also bought the Fender Pack for Amplitube which is really nice. I also have almost all the effect boxes in both Ampkit and Amplitube. In Ampkit I also bought the Bassman amp module. Now I also bought the GK amp app. All apps work far better on the iPad then on the iPod gen2 even though all apps and specially Amplitube came with updates that resolved lots of issues on the iPod gen2. Less noise and better performance in generally. One can use the play along without any hick-ups. Here are my remarks for the apps (with focus on the performance on iPad): Amplitube: The overall best app. Great GUI and lots of modules for bass. I love the SVT amp paired with the 15 cab or the 4x12B cab. Also the Vox AC30 with 2x12, 15 or 4x12B cab is great for more over-driven British tone. The Bassman 59 is also nice, paired with the limiter and the 4x10 cab one can have decent clean headroom or vintage dirty tone. Paired with my CV P and old rounds... vintage indeed. The Marshall guitar amp paired with the 1x15 cab and the Fender comp can give some nice dirty tone ala Cream and Jack Bruce. If one wants the Geddy or the Squire tone, well, the SVT with with the Tube Screamer or the Distortion box will come close. The Ampitube have a very good recorder: 8 tracks, with pre and post processing. The play along is good, BUT, one have to import the song into the program, directly form the iPod library. The file will be converted to a wave file, so in some way waste of space. But here you can play the song faster or slower. Really great for learning a song. Amplitube is going to come with GK and Orange modules in the future!!!! Can't wait! Ampkit: Almost as complete as the Amplitube, but the recorder is only one track, the play along have only start and stop, you can not stop in the middle of the song and start again. The file is played directly form the iPod library, thus not converted to wave. The Ampkit have som nice drum tracks to practice with. Overall, not as good as Amplitube for bass. But still nice software. GK: A simple amp simulation. I like it. It looks like a GK, sound like a GK. The software is light as there are no tuner, additional effect boxes or recording possibilities. The Play along is good. File played directly without importing/ converting to wave. One can stop in the middle and continue. But you can not play the song faster/ slower. The GK app is CHEAP! So, from my experience: If you want the overall app buy the Amplitube. It does ALL. If you want just an amp modulation with play along capabilities the GK is the answer. The GK lack a tuner, it should have this function!!!