I have both iOS devices and with keyboards. I could be much more productive if I could do Alt-Tab / Command-Tab app switching using my keyboard. Is there any way to do this? Is there any way to switch between the two most recent apps or anything similar?
No, there isn't a way to do this. As an alternative, I would suggest enabling multitasking gestures (Settings > General > Multitasking Gestures). With them on, you can switch to the next/previous app with a four-finger swipe, instead of bringing up the multitasking bar. You can actually swipe through all of the apps in the multitasking bar, in the same order (order of last use). Note that getting to an app through this gesture does not change their order, so if you swipe left to get to an app, you will swipe right to go back.
I haven't tried it, but if your keyboard has a home button, you should be able to double click it to get the task switcher up. So it seems it should be easy.
Method copied from source
First, you activate VoiceOver on the iPad, and specify that a Home button triple-press will turn VoiceOver on or off. Then, you just learn a few simple commands and practice, and a lot of common quickie things (like app switching, scrolling through web pages, etc.) become possible without taking your hands off the keyboard. This is most useful when, e.g., you’re writing a blog post on the iPad, in the WordPress app, using the keyboard, and you want to hop over to a web page for a second to check something. Now you can do that without your hands leaving the keyboard, as follows:
- press ctrl-opt-H twice to bring up the app switcher
- press right-arrow to move to Safari, then ctrl-opt-spacebar to tap
- press opt-down-arrow to scroll in Safari (or, if needed, right-arrow to move to the page selection button, etc.)
- when done, switch back, via ctrl-opt-H twice, then right-arrow as needed, then ctrl-opt-spacebar to tap
If you're jailbroken, you can install BeeKeyboard and Multitasktures to do this.
Edit: Below is pre-iOS9. See updated (accepted) answer below from Anonymous
In brief: It is possible, but not quite "alt-tab". Enable VoiceOver.
This is described here: http://decadentwaste.net/2011/03/navigate-using-a-bluetooth-keyboard-on-your-ios-device/
I believe this is also referenced from Graham Wheeler's answer. Sorry that I can't comment directly.
The article describes how to use the built-in "accessibility" options to navigate pretty much anything with the keyboard. I've tried it out using the basic Apple Wireless keyboard, which doesn't have a home button for example. I can now scroll, launch apps, switch apps from the keyboard.
Note, for comfort, I recommend setting the home button to enable/disable this voiceover mode. In addition, since the default for VoiceOver is to use spoken navigation for the UI, Opt-Control-S will mute the voiceover speech.
It's been added in iOS 9 or it was on before. I use an Anker Bluetooth keyboard. I can Alt Tab just fine with it!