I've contacted them for info on their SDK but there's nothing available yet. I will look into doing this if it can be done. I missed the Kickstarter campaigns though so I won't have a device anytime soon to try. It would be the killer feature for ExpoDev.
I will look into this again but it may not be doable. See my comments on this idea for more details.
Currently, this is by design. Apple provides no sanctioned way to keep the screen "alive" for apps like ExpoDev. It can be done by using tricks but these come at the expense of battery life and whether Apple's app review team allows them.
ExpoDev tries to be smart about this though - if the device goes to sleep or if you switch to another app while a long exposure timer is running, you will get a pop-up alert notification 30 seconds before the exposure ends that will allow you to jump back to ExpoDev. You have to allow ExpoDev to show notification alerts in your device settings (which is the default unless you change it). This works as long as the exposure is longer than 30 seconds, which should cover most device sleep timeouts.
Saving the location will definitely be added once the exposure notes are expanded. In fact, the exposure records already have a place to store this - it's just not being filled in or shown yet.
Something will happen on this front but I am planning on an online backup solution like Dropbox/SkyDrive/GDrive rather than email. This way exposure records can be backed up, archived, re-loaded, etc… it would also facilitate future off-device PC/Mac viewing & printing.
Just an FYI, all exposure records are backed up to iCloud if you have backups for your iOS device turned up. And you can also copy them out of the device as indiidual files by connecting your device to iTunes (there is an article on this help site with details).
That said, I will look into other ways that they can be copied off the device, perhaps Dropbox and/or SkyDrive as that probably makes the most sense for working with these files.
I agree that this is useful and was something I was sad to see removed, however there just wasn't room for it anywhere in the new UI. I am exploring ideas to expand the metering notes in general down the road and will most likely find a place for this feature fit in there.