I too was a long time Listpro user in Windows Mobile. I have purchased the pro version of Checkmark for my Evo 3D and I am okay with it except for one feature I cannot figure out. I have emailed them and they haven't responded. I wonder if you've figured this out.
I have made a shopping list. I want to flag the items for purchase. The list has over 500 items in it, so usually I want to search for the item to flag. You need to be in edit mode to flag an item, but it seems that there is no way to search for an item in edit mode and then find it and flag it. Once search finds the item, the flag option is not available and once you exit search mode, the found items are no longer shown (the whole list is). This makes it very impractical to use as a shopping list where one wants to find and flag a few items rather than scrolling through the entire list. Isn't there a way to do this?