... is very accessible. I've reviewed it on applevis.
    http://www.applevis.com/apps/ios/education/ham-morse
 
I use it in conjunction with the G4FON Koch trainer; this one is easier to
carry in my purse! G4FON gives you more practice in real-world conditions.
This app is better if you are trying out different learning methods as it
supports them all.
 
One important point: if you choose the Koch method with this app, the add
and remove character button labels are reversed. So choose remove to add a
new character and you'll do fine.
 
--Debee [KF6BKR]\