Is there a cell phone-based cycling app for just mileage & time?

[cgolvin]

I know you said cell phone but the "outdoor cycling" activity on an Apple Watch will do exactly this, and I'm sure the same is true of Garmin and other smart watches.

[glepore]

RWGPS as others have said.
Wahoo has a free app that doesn't require their computer and will track time speed and distance, along with power if you use a powermeter. The others don't do power.

[RoosterCogset]

In the vein of free apps, the Road iD app will track your distance and time, and in addition send a notification email in case of potential crash to your designees.

[merlinmurph]

For battery iseues, pre-cache the maps and go into airplane mode. GPS still works, and as a bonus, you won't get any annoying calls....

[54ny77]

Great tips here, thanks!

And yes I was looking for free app (I forgot to mention it in original post).