The app automatically changes to speed (km/h) when I am recording a a cycling activity, and pace (min/km) or heartbeat when recording a running activity. It is also compatible with the Danish (European) iPhone setup - under RunKeeper I had to set up using US settings to eliminate the Runkeeper "box" bug in the display when using Runkeeper, and then change back to the Danish settings afterwards. This is a great improvement!
I met a friend while out running yesterday and was able to pause and leave the Pebble/iSmoothrun screen, go to the music screen and stop the podcast I was listening to, restart the podcast and return to iSmoothrun and continue my run without issues - all without digging my iPhone out of my backpack!
The current version only allows (heartbeat or) current pace, which is delayed by about 10-15s so only really useful if you run relatively consistently. However, I understand average pace or workout average pace may be an option in future versions.