If you want to see how fast your going, how many amps, aH etc, you have to have your phone mounted somehow. The Speedict device is doing all the measuring and sends info to your phone, so its operation doesn't get interupted if you then start using any other ap like a navigation program or the phone, or you can switch the phone off and put it in your pocket, then, each time you go back to the Speedict ap, it'll show the latest data as if you'd had it on all the time. The Speedict logs the data as well, so when you want to see the charts and totals, they're all there for you regardless of what you did with your phone during the ride.
The Cycle Analyst has its own display, so is a permanent fixture on your bike, which means that it's a bit more convenient. It works just like a normal bike computer except that it has additional info about your battery. Additionally, it can limit speed, current etc with a bit of extra wiring. In the latest version are some additional features but I can't remember what they are. You can find them on the Ebikes.ca website.
This is what a Speedict looks like on a Galaxy s2. Thedisplay is configurable for what parameters you see on the screen. You can have satnav running at the same time and switch between the two, but Speedict has its own map mode, so you can see where you are on the map:
Cycle Analyst looks like this:
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