Trackmaster is quite easy to use: simply create some split points using a maps overview (so make sure to do that when you have a fast network available, e.g. in advance at home over WiFi). Then you start it and it starts recording as soon as the first split point is reached.

Since I did not have a good mount for the phone, I just kept in my pocket. Worked fine.

There's a lot of data to look at and export after the fact:

Lap Top Speed (mph) Avg Speed (mph) Dist. (mi.) Time Session 2: 1 83.33 57.12 2.80 2:48.768 2 87.25 56.14 2.81 2:56.300 3 83.33 56.35 2.81 2:55.109 4 78.29 55.13 2.82 2:57.440 Session 3: 1 73.81 51.11 2.84 3:10.768 2 88.92 58.16 2.86 2:49.042 3 95.35 61.41 2.82 2:38.859 4 97.87 63.08 2.91 2:36.553 5 97.87 62.48 2.89 2:38.652 6 102.67 59.31 2.87 2:45.343 Session 4: 1 81.08 51.25 2.80 3:10.088 2 86.12 60.44 2.80 2:40.272 3 87.24 61.21 2.79 2:37.079 4 86.40 57.85 2.81 2:45.685 5 95.94 60.41 2.82 2:39.584 Session 5: 1 94.23 54.89 2.79 2:56.366 2 99.93 61.79 2.79 2:37.853 3 99.88 61.85 2.83 2:39.735 4 101.30 60.57 2.84 2:42.864 5 101.34 61.63 2.83 2:39.595 6 91.94 62.30 2.83 2:37.489 7 88.36 60.04 2.85 2:43.987 Session 6: 1 93.67 58.58 2.80 2:44.766 2 97.58 58.47 5.02 5:24.291 3 101.22 60.45 2.84 2:41.633 4 103.45 64.41 2.84 2:34.172