user22: Specifically I'm looking for Armory-like functionality where the transaction can be generated on an online system, transported to an offline android tablet or netbook via USB or QR code where it can be signed, then transported back to an online system where it can be broadcast.

user24532: The app "Bither" does exactly what you want (available for iPhone and Android). QR-codes are used for transfer (instead of USB stick in case of Armory).

user32049: Yes Bither is exactly what you are searching for. From my point of view Bither is quite underestimated. Due to the cold storage functionality with a 2nd offline phone Bither seems to the be the safest wallet availabe for mobile phones (Android, iPhone). In addition it exists also for Windows.

user6756: Its not exactly what you want, http://mycelium.com/ for Android does it the other way around.
You keep your private keys safe in QR-code format on a paper or a offline device, then you scan it when you want to make a transaction. Mycelium signs the transaction and forgets about the key.
I tried to scan with my Android device offline, but it does not work. To be able to select previous outputs to send in the transaction, you need to be online.
I don't know of any Android app that can take a raw transaction (by QR-code, SD-card, OTG, Bluetooth, NFC or Chirp.io) and sign it offline. 
I hope this feature will be implemented soon.

22: <p>Specifically I'm looking for Armory-like functionality where the transaction can be generated on an online system, transported to an offline android tablet or netbook via USB or QR code where it can be signed, then transported back to an online system where it can be broadcast.</p>
 24532: <p>The app "Bither" does exactly what you want (available for iPhone and Android). QR-codes are used for transfer (instead of USB stick in case of Armory).</p>
 32049: <p>Yes Bither is exactly what you are searching for. From my point of view Bither is quite underestimated. Due to the cold storage functionality with a 2nd offline phone Bither seems to the be the safest wallet availabe for mobile phones (Android, iPhone). In addition it exists also for Windows.</p>
 6756: <p>Its not exactly what you want, <a href="http://mycelium.com/" rel="nofollow">http://mycelium.com/</a> for Android does it the other way around.</p>

<p>You keep your private keys safe in QR-code format on a paper or a offline device, then you scan it when you want to make a transaction. Mycelium signs the transaction and forgets about the key.</p>

<p>I tried to scan with my Android device offline, but it does not work. To be able to select previous outputs to send in the transaction, you need to be online.</p>

<p>I don't know of any Android app that can take a raw transaction (by QR-code, SD-card, <a href="https://en.wikipedia.org/wiki/USB_On-The-Go" rel="nofollow">OTG</a>, Bluetooth, <a href="https://en.wikipedia.org/wiki/Near_field_communication" rel="nofollow">NFC</a> or <a href="http://chirp.io/" rel="nofollow">Chirp</a>.io) and sign it offline. </p>

<p>I hope this feature will be implemented soon.</p>
