Collins Cobuild Student's Dictionary is pretty much the accepted standard for English learners, as they offer clear definitions specifically designed for non-native English speakers.
This Pocket PC version works very much as you'd expect. Tap in a word, and you'll be taken to its definition. You can also scroll up and down, to read its neighboring entries, just like a paper dictionary.
You can also check for verb forms - past, continuous and so on - so you can be sure to get the right version you need. There is also a number translator - type in any number, and it will be printed in word form. Finally, you can copy and paste anything and use it elsewhere on your Pocket PC. Visually Collins Cobuild Student's Dictionary is clear and functional, without any unnecessary flashy graphics.
Collins Cobuild Student's Dictionary is an ideal dictionary for beginner and advanced English learners alike.