How to get old iphone app?

Try updating your iOS. The new app has no problem with the iPad hardware.

I take it you have an iPod touch - the iOS on the second gen iPod touch can't be upgraded past 4.2.1 as you probably know. You won't be able to get the old version from the iTunes store. There may be a couple of things you can try though. 1. Try backing up your purchases from one of the iPods that does have the working version...... In iTunes, go to your library, look under apps and see if there is a version of the app there already - you can right click on it and then choose get info - the version number is in the second panel on the top right. If the version is the one you need for the touch, then just connect the touch and drag and drop the app onto it. If it's the current version of the app then delete it from the library. Go to files -> Devices -> transfer purchases from (name of device here) When they've transferred then go into your app library and if you can see the original Sonos app then check the version number again. If it's the one you want then disconnect the iPod, add the one that doesn't have the app and then drag and drop the app onto it from the library..... 2. You could try backing up one of the touches with the app you need on it and then applying that backup to the touch without the app. Obviously this would wipe the touch without the app. Connect the device that does have the app. In iTunes, go into your device and under the summary tag you'll see Backup - choose "this computer" and then "backup now". When the backup finishes then disconnect the touch. Connect the one you want to put the app on, then again, go into the device and under the summary tag click on restore in the top right box. When the restore has finished, as part of the setup it should ask if you want to restore from a backup - select the one you've just made. Both these methods are a bit of a Hail Mary, and I can't guarantee it will work but you can give it a go.

I take it you have an iPod touch - the iOS on the second gen iPod touch can't be upgraded past 4.2.1 as you probably know. You won't be able to get the old version from the iTunes store. There may be a couple of things you can try though. 1. Try backing up your purchases from one of the iPods that does have the working version...... In iTunes, go to your library, look under apps and see if there is a version of the app there already - you can right click on it and then choose get info - the version number is in the second panel on the top right. If the version is the one you need for the touch, then just connect the touch and drag and drop the app onto it. If it's the current version of the app then delete it from the library. Go to files -> Devices -> transfer purchases from (name of device here) When they've transferred then go into your app library and if you can see the original Sonos app then check the version number again. If it's the one you want then disconnect the iPod, add the one that doesn't have the app and then drag and drop the app onto it from the library..... 2. You could try backing up one of the touches with the app you need on it and then applying that backup to the touch without the app. Obviously this would wipe the touch without the app. Connect the device that does have the app. In iTunes, go into your device and under the summary tag you'll see Backup - choose "this computer" and then "backup now". When the backup finishes then disconnect the touch. Connect the one you want to put the app on, then again, go into the device and under the summary tag click on restore in the top right box. When the restore has finished, as part of the setup it should ask if you want to restore from a backup - select the one you've just made. Both these methods are a bit of a Hail Mary, and I can't guarantee it will work but you can give it a go.

Thanks for helpful reply, Mark.
I'll post a reply for "how to" next, but your responses/help got me 80% of the way there 🙂

It can be done ! :

When Mark said "iTunes" he means iTunes on the desktop (PC in my case), not iTunes on the Ipod Touch2.

Also, to understand his instructions, you need to turn on the menu bar! (My new iTunes install had it turned off - right-click on "two rectangles", top left, select "show menu bar" to get the "File" option plus others)

Then go to edit-prefrence-advanced and un-check "check for new updates automatically", otherwise it keeps on over-writing your old, compatible apps with new, unusable ones!

The "library" is viewable by the labelled button, top right.

For an iPod Touch Gen2, you need Sonos V4.3, NOT 5.  Don't be afraid to delete your library one, it won't delete the one on your iPod (a concern when it's your only existing copy!)

Then as Mark said:
"Go to files -> Devices -> transfer purchases from (name of device here)"

Provided the auto updates are turned off, you'll get the OLD, useful one in your library.

(Also transfers any others here at this time eg OLD Google Earth, in my case, IF you've deleted New, incompatible ones first)

Then you can do a Full backup of the ipod WITH the wanted version on it.

Finally, I then restored that backup to the iPod I wanted to get the software on (as for me, a full clone was be ideal).
 Bingo, a dupe with the old app running.

If you don't want to clone it, though, I was stumped - as I couldn't understand the second bit of Mark's first option:
"add the one that doesn't have the app and then drag and drop the app onto it from the library....."

the (ipod device name without Sonos 4.3) doesn't appear anywhere on my screen to drag & drop it to - so perhaps Mark could elaborate.

But thanks, Mark.
Why don't Sonos keep the old version available? As say "Sonos for iOs 4.2, UNSUPPORTED", or some some such.  Ipod Touch Gen 2's were a good, cheap alternative as a quick-and-dirty controller for general use - but are now shut out unless you already have a copy of the app to hand.

"add the one that doesn't have the app and then drag and drop the app onto it from the library....." I meant disconnect the iPod touch that you've transferred the purchases from, then connect the iPod touch that you want to put the app onto and drag and drop the app from the library to that iPod in the bar on the left of iTunes. Regardless, am glad I could help even if only a little bit as I wasn't sure if it would even work.

Thanks for the detailed directions, those are going to work for getting the 4.3 app installed which will work with the current version 5.0 of Sonos. 

Another way to download the app is to go to your App Store on the iPad and click Purchased. Then scroll through the listing and you'll see Sonos Controller for iPad (with the blue icon). You can install that and you'll have the 4.3 software. 

Later this year, we'll be releasing another update where the older version of the app, pre-5.0, will no longer function with Sonos. Until then, you'll be able to use the iPad first generation and other iOS devices running Sonos Version 4.3.

We always encourage using the latest version of the software as they include new features, updates, and other improvements.

The old version will not work anymore. As soon as I launch it , it states an update is required.

"add the one that doesn't have the app and then drag and drop the app onto it from the library....." I meant disconnect the iPod touch that you've transferred the purchases from, then connect the iPod touch that you want to put the app onto and drag and drop the app from the library to that iPod in the bar on the left of iTunes. Regardless, am glad I could help even if only a little bit as I wasn't sure if it would even work.
Thanks Mark
For info, my Vista32 iTunes V11.1.5.5 doesn't have a bar on the left ... 
...(perhaps I misunderstand)
...unless you mean a button on the toolbar, which is labelled "ipod" with an up-arrow beside it - on the right in my installation

Not this time.. V5.0 didn't offer any improvements whatsoever. You have ruined the controller. Let me roll back to v4.3 or refund my equipment.

"Another way to download the app is to go to your App Store on the iPad and click Purchased".
This on IPOD (Touch Gen2), not an IPAD.  I don't see anywhere to click "purchased".

"We always encourage using the latest version of the software as they include new features, updates, and other improvements"

That's fine if it doesn't disable a whole raft of perfectly good hardware from achieving a useful job.  Not having V4.3 for an iPOD (gen2) available for download means that no-ne can make use of those devices on a SONOS system if they have them or can get them.  

I can understand not SUPPORTING the old versions, but removing access to the old app does positive harm to the perception of SONOS green/sustainability credentials.