[Omaroo (Chris Malikoff)]

Mick - It's not possible to develop a universal red screen app for iOS at this stage. If you developed and ran a red screen app of sorts, and then you fired up another app (such as a browser, or email), the second app takes over and pushes the first into background mode. You can't run two at once in the same screen real estate - which is what would be required. Apple would need to implement it at operating system level. I believe that they would get quite a few requests from not only astronomers, but aviators, bushwalkers and in-vehicle GPS users. Here's hoping. The other problem with an app is that you'll traverse other applications as you go from screen to screen and blow your night vision in a second as you come across something with white in it - like the home screen.

If you go to settings and choose the General/Accessibility setting you can alter the "Triple-Click Home" item to inverse your screen colours universally - so you see white on black. This dramatically helps in some circumstances.

Cellophane is junk. It's crinkly, not stiff enough and is not of adequate colour density unless you use multiple payers - and then the capacitative touch screen doesn't work properly. I use a commercially-available red film designed for the purpose - and used mainly by laptop users. Touch screen sensitivity is maintained - I use it all the time and it works very well. Just remember to have the shiny side up, as the other (colour ink) side gets wet with dew and starts to go a little soft and make dragging your finger across your screen tough going. Not sure about what cases there are for the iPad 2 if that's what you have, but my original iPad's standard case is ideal for the job as you can tuck the film under the edges of the case and it holds firm while dragging.

Nice thing with this is that it works with all the apps that I might want to visit during the night - like weather, or Safari, mail or whatever. Good astronomy apps such as Sky Safari, RedShift and the like will have a red screen mode - but that's only in-app which means you blind yourself when leaving it for another app during the night.