Music recording and collaboration on the iPhone

Been looking at iPhone music apps. This is what I want to be able to do:

Essential

1. Open recordings sent to me (by text or email) without having to connect my iphone to a computer, then

2. Basic editing of those recordings, so cut/crop/reorder etc. 

3. Record additional tracks alongside the original recording (overdub). Both via mic and line in (I.e. vocals and guitar) while listening to the original recording

Nice to have

4. Some more advanced wave editing, e.g. EQ and increase volume.

5. Use other samples and instruments in a multitrack editor

6. Ability to share multitrack/ project files without connecting to a computer

7. Allow commenting on tracks (like soundcloud)

GarageBand 

Free, but £3 to add all instruments

I have been using Garageband for a while, but mostly for my own amusement using apple's samples and occasionally MIDI instruments. GarageBand allowed (5) and (2) but none if my other criteria. 

Frustratingly, GarageBand does not allow you to do (1). You have to connect to iTunes on a computer to share recordings with each other. Annoying, and this is what led me to researching other apps.

Supports AudioPaste but not AudioCopy.  Is an Audiobus output but not an Input.  Note that the new version v2 insists you have iOS 7, which i dont have (as i am deepky suspicious if apple 'upgrades'); not sure if its possible to get v1 which I have.

Handsfree headphones/mic and iRig 

Around £20 for headphone socket version, lightning socket version around £60.

Recently I realised that you could use the handsfree headphone/mic to do (3) for mic/vocals only. I also bought the iRig adaptor which allowed me to do (3) for line-in/guitar as well. I think you need to buy the expansion to do this with amp and pedal effects in garageband. 

[edit: at first I noticed some connection crackling when using iRig with Amplitube, and it seems to have gotten worse - the iRig build quality seems very poor. May look to get a refund and buy another brand]

Music Studio £10.50

This seems to do all of my essential requirements (1), (2) and (3).  Of my nice to haves it seems like it may do a bit of (4), it can do (5) and comes with quite a few midi instruments but not any samples/loops. I think I read somewhere it could store project files in Dropbox which would allow you to collaborate, i.e. (6).

Supports AudioPaste and AudioCopy, and is an Audiobus output and Input.

Multitrack DAW £7

This does all my essential requirements too. One thing I noticed is this takes up very little storage space on the phone, unlike GarageBand or music studio which are huge. Doesn't come with any samples or midi to play around with, i.e. (5).

Allows AudioCopy and AudioPaste. Audiobus as output only, not input.

TwistedWave wave editor £7

Only does (1) and (2), not (3). Does (4) too. Allows copy and paste and is an Input or output in Audiobus.

Audiobus £3

Doesn't do any of the above but allows you to link other apps together, so for example you could play your guitar through Amplitube Free as an Audiobus input and record it in another app as an Audiobus output.

In Summary:

	GarageBand	GarageBand with expansion	Music Studio	Multitrack DAW	TwistedWave wave editor
Price	Free	£3	£10.50	£7	£7
Open recordings sent to me (by text or email) without having to connect my iphone to a computer	No	No	Yes	Yes	Yes
Basic editing of those recordings, so cut/crop/reorder etc.	Yes	Yes	Yes	Yes	Yes
Record additional tracks alongside the original recording (overdub). Both via mic and line in (I.e. vocals and guitar) while listening to the original recording	Not sure but I think so, but with no guitar effects	Yes	Yes	Yes	No
Some more advanced wave editing, e.g. EQ and increase volume	No	No	Maybe some	Don't think so	Yes
Use samples and MIDI instruments in a multitrack editor	Yes, not sure if it comes with any samples though	Yes, you get a bunch of samples	Yes, comes with plenty MIDI instruments and some drum loops but no samples	Yes to samples although doesn't come with any, don't think it does MIDI instruments but not sure	No (this is not a multitrack editor)
Ability to share multitrack/ project files without connecting to a computer	No	No	I think so, via Dropbox	Don't think so	N/A
Copy/Paste to/from other Apps	Paste only	Paste only	Yes	Yes	Yes
Audiobus	Output only	Output only	Input and Output	Output only	Input and Output

Other Apps considered (either didn't meet criteria; didn't provide enough info without paying to judge; iPad only; or didn't work)
ThumbJam
Hakusai wave editor [I was unable buy the expansion to allow AudioCopy; simply didn't work]
n-Track Studio Multitrack Recorder
JamPipe
Reforge

This website is worth a look too http://www.iosmusician.com/