I think a window tablet would be better, but the iPad is in hand.

what did you use for a soundcard?  the RME?  does it connect to iPad?

When I first read this I thought he had made an 8-track tape!
 
LOL

I used the RME UCX and the iPad app Auria.
 
With Auria, your iPad matters...
http://auriaapp.com/Support/auria-support
 
The iPad I have (it's a long-term loaner), has a little more than 8 GB of available storage so I have a theoretical limit of recording 8 tracks for 2 hours at 24 bit 44.1. I haven't pushed the limit.
 
I had to buy this hardware connector.
http://smile.amazon.com/Apple-Lightning-Card-Camera-Reader/dp/B009WHV3I0/ref=sr_1_2?ie=UTF8&qid=1438436214&sr=8-2&keywords=ipad+camera+connection+kit
 
and this iPad app 12.99
https://itunes.apple.com/us/app/auria/id524122834?mt=8
 
and I bought the RME TotalMix app 3.99
https://itunes.apple.com/us/app/totalmix-fx-for-ipad/id739965887?mt=8
 
If you have a UFX, then you don't need Auria. You can record directly to a thumb drive from the UFX.
 
The UCX is smaller than the UFX. The UCX doesn't have any on-board memory, so you need to buy an iPad app for the recording. For this I bought Auria which works fine.
 
....
 
I'm still interested in a Windows tablet so I can run Sonar, TotalMix and DigiCheck all at once, but the iPad thing was pretty cool for $17 USD (I didn't pay for the iPad).
 
I have my UCX and my Quad Mic Pre racked up in a single U so I can carry it in a bag like this... 
http://www.musiciansfriend.com/accessories/skb-1u-audio-soft-rack-case
and have 6 nice Pre-Amps, EQ and Compression on every Channel. Direct Monitoring. Reverb and Delay. (All FX are in the UCX). And 2 channels for guitar/bass direct with high-z instrument settings. AutoSet gain on 4 of the channels. 48V Phantom on 6.
 
Since the iPad RME TotalMix works in Class Compliant mode, I can use the iPad to configure the RME, then unplug the iPad and plug in a computer booted to Linux Ubuntu Studio and record to Linux with basically unlimited storage.
http://ubuntustudio.org/
 
It's a real bummer not having TotalMix for Linux. It would REALLY help. I don't think I would have ever messed with the iPad except that I really miss TotalMix when using Linux to make recordings. I need to be able to route the vocalist to the PA when making recordings. Doing it through Ardour http://ardour.org/ means that I have to keep the latency low.
 
The other day, making a 16 track recording using Linux Ubuntu Studio, I set latency at 256 samples and routed the Vocals through Ardour to the PA. After about 1 hour of recording, I got an audio glitch writing to the disk. I'm not sure if it was a disk issue or related to the load and the latency setting. But it's better if I can just route the audio through the RME and boost the Sample Buffer to 2048 (Max on UCX at 44.1).
 
 

I've used my UFX + iPad running Cubasis and Totalmix to record a few tracks at a friend's house. Works very well. Unlike using a USB stick in the UFX there's visual feedback which is useful.

I have used my iPad and Auria to make scratch demo songs while songwriting. I believe I have only recorded up to 4 tracks at one time and I was using just the built in mic and no interface. Both of my Scarlett's say they will work with the iPad, I just haven't been in the situation to try it yet.

The results were not bad at all for the crude circumstances I would record in.

I have an Android phone (S3) and tablet (Nexus 10), and have no plans to switch to Windows mobile devices because I just love the integration between PC, phone and tablet. It's been working very well for me for some time, so I have no reason to change. That said, what about mobile recording?
 
So I did some checking and testing and settled on Audio Evolution Mobile for my Android DAW. Less than US$10. An in-app purchase to add their USB Class Compliant driver was also less than US$8.
 
Good post on their support for USB audio i/f:
http://www.audio-evolution.com/manual/doku.php?id=usbaudiosupport
 
List of supported and non-supported audio interfaces and Android devices:
http://www.extreamsd.com/index.php/2015-07-22-12-01-14/usb-audio-driver
 
The DAW itself:
http://www.extreamsd.com/index.php/aem-1
 
This is an elegant solution that works very well. They claim it will also run on my S3, but I haven't tried it. After I added the USB driver support, I plugged my paperweight, but class-compliant PreSonus AudioBox 44VSL, through the appropriate cable, into the Nexus 10's USB port and AEM recognized it and configured itself properly for that i/f's inputs and outputs.
 
At the moment, I'm just using it for recording, and then moving the raw audio stems to SPlat.
 
If you have a compliant Android device and a class-compliant audio i/f, Audio Evolution is a nice option.
 
Edit: This is especially handy at the moment, while I'm waiting for Tascam to update the US-16x08 driver for Win10.

This is very interesting - I already have that USB/Camera adapter that I use for plugging my oxygen midi controller to my ipad and I have a presonus 2x2, I think I'll go download Auria and see how well it works.

well that didn't work. The Presonus uses USB power only and I get a message on iPad saying the device uses too much power.

Beagle
well that didn't work. The Presonus uses USB power only and I get a message on iPad saying the device uses too much power.

Yup. You're gonna get that with any of the buss-powered interfaces. You need an external powered USB hub, something like this one:
 
http://www.amazon.com/Ama...adapter/dp/B00DQFGH80/