What GPS tracking iphone apps (cycling and running) can be used without a 3G signal?

I have been using both endomondo and mapmyride for my running and cycling.
When I came to track my mountain biking neither of the apps would start a workout because I was out in the sticks with no network connection.
I wasn't expecting any live maps, but was expecting either one of the above to be able to track my coordinates by GPS, to be uploaded later.

Shame really because I like the apps.

Do they actually works without a network signal and I'm missing something?

Not sure of this as I think the signal still works with the gps even with no signal. Not too sure of that but I thinks so. It might be the program needs to start before you lose signal. It is worth a try and then you can edit out that part that you drive if it continues to work

Mapmyride?

My understanding is there's a difference on implementation on how it locates. Some phones use straight GPS, but some use a combo GPS and cell signal. So it might be more of a limitation of the device as opposed to the app. I'm a phone idiot, but I do use handheld GPS for other things.

Strava works without a cell signal for me. It still needs GPS, but not a network connection.

I have a question. I assume that you cycle/run pretty much the same route all the time. Why in the world do you need a GPS? If it is just to track time then why not just use a watch, or if your phone is welded to your hand you could check the time there too.

Several of my customers have asked me to carry them but not a single one can tell me why they need one. If I got just ONE good answer it might encourage me to carry them.