I guess we'll just have to wait for usage and development to evolve this kind of thing until its all things to all men.
I think the memory map app could only be better on an Android rather than an Iphone since the Android is easier for devlopers to work with since the restrictions are fewer (it supports Flash unlike the Iphone for example)
The memory map app works well for me on an Iphone and I'm sure other vendors will produce competitors eventually. The competition will drive up the functionality and the usability, though perhaps not the price since Memory Map have set the bar so low (£20).