Rob
Not sure you can have more than one app in a context, but you can definitely create a Task called (for example) "GPS On" and tie that task into the apps you have mentioned.
You may find that you have a problem with the Navigation app though. In fact could you please check/confirm this for me? When I ask Tasker to turn on GPS when I start Navigation, it doesn't quite react fast enough to stop Navigation being patronising and asking me if I want to Turn GPS on! It is not a dialogue box you can skip/cancel past! You can see that Tasker HAS turned GPS on from the icon in your notification bar, but the Navigation app seems oblivious to it. Clicking on the OK button takes you to the screen to turn GPS on, which automatically turns it off, just so you can turn it on again!!!! Arrrrggg!!!!
There is a setting within Tasker which says how fast it reacts to apps being launched. It's default is 1500ms. I have tried turning this right down, but it does not seem to get GPS turned on before the app looks to see if it is turned on.
For now I have done a work-around by creating a widget next to my Navigation shortcut which turns on the GPS (and turns up screen brightness and ups he volume level) before I start Navigation.
Oh and for some reason, if I asked Tasker to JUST turn up the brightness when launching Navigation, it would cause the Navigation app to close seconds after launch. No FC or error messages. Just bombs me back to home page.
Anyone else had similar issues with Navigation + Tasker?
Had the same problem and found the solution. it involves creating a widget that enables the GPS first, then loads the Navigation App. As a plus, you can add the Navigation Icon. Then you create and task that turns off GPS whenever you close it.
