would be nice to race against yourself (older recorded tracks) an you could see, if you are faster or slower than on former laps. This should be shown live on the map including the gap to yourself in meters or seconds.

depending on weight and height...

Make the application able to collect data from heart rate belts!

Runcoach is your personal trainer just in your pocket . Create your own dedicated wellness plan around you with simple way, build any workout program based on your possibilities, make a specific training target and follow it day by day (schedule) .
During the workout your personal trainer talk to you in your ears over music soundtrack to get any instruction on current exercise such as step, mode, kalories counter, and more .

I would like to have the possibility to manually add workouts i have done without using runstar.

If the weather is bad outside i don't like the idea of taking my shiny phone with me while running.

I love seeing my speed on the graph, but I think it would be great to have it show up on the map too. If you were to use different colors or gradients on the map, instead of just a solid blue line, I think it would be even better. Even if it's just a few colors (green, yellow, red), it would be a nice addition.

Challenge another user to run faster on a distance you have run, or longer during a month, etc.

I tend to run on the treadmill instead of outside at this point. Since this app only uses GPS to measure distance, the only thing I get from it is the total time I ran. If, like how Nike+ works, this was a glorified pedometer I could use it in other applications as well. E.g. leave it running for the whole day to see how far I've walked over the course of the day w/o killing the battery on GPS.

I have logs at other places that I want to have as part of the history in runstar (cardiotrainer, mytracks, etc). I need a simple way to import this information either automatically or simply by manual input.

Crashes are inevitable, especially if the phone is overloaded. Runstar stores what it had and saves the workout, which is great, but it would be perfect if I could reopen that workout and have it continue.

Easy readable statistics of average pace and time between each km or mile. Now i have to read the time from the map, and count valueas in the excel

Use the headphone button to control runstar music player

When your pace drops below a preset min/mile start the power up automtically.

The line graph is too small to be useful. Also, the elevation is always based on zero. This make the elevation useless. It should start at your beginning elevation. All other running apps provide the functionality.

Enter a target pace per KM/Mile and give audio alert when too slow/fast by x%

you need the ability to start it on a headset button, and will also need to think about be able to control the music on this too. One idea is you put in the distance you want to run and the headset once started wont stop on a short button press, but will on a long press. Also needs audio cues as feedback on the press, for both when gps has been aquired and starting on just a timer.

not only min/km