The II App is good for getaway alerts and checking them, as sometimes there is a delay between inventory going in and an alert going out, so when you select the alert, you get a white screen, as the inventory isn't there. You can set up to 14 separate alerts and each alert can be for a max of 90 days date range duration and you can do those upto 2-years ahead.
There is no function for exchange alerts, other than setting up a request, but some resorts do put inventory into getaway and exchange so getaway alerts can be used for those.
There is also the mobile website, not great, and the full website via a mobile device, which isn't bad.
The App presents inventory by date and then by resort, so if you search by several resort codes or an area, its different to how the website displays it. I prefer the format of the website of grouping availability by resort.
When you do vacation search on the App, it can default to searching for both getaways and exchanges, which can appear to give odd results, so double check the setting at the top of the screen before you search.
I've never got the resort directory to work sensibly when I want to look up a resort in a location, it might just be me....
Now and then people report different results from searching the App vs the website, its difficult to tell whether that real or a timing issue or user error, but it can be worth using both just in case.... Retrading via the app can also give better results then via the website.