Uncle Josh's maps are simply blank line maps that are copied from the book or printed from the cd. I have the cd and use it, but there are maps free online to print.
Then and now Bible maps is a great resource to have on hand to see how the holy land has changed. If there is an iPad version, I've not seen it yet. I do think it is a worthwhile resource to have. An iPad version would be a great idea!
Wall maps are nice because of the big size, but not necessary. There are websites and apps you could use instead. However, we like our wall map as it makes seeing things easier when doing map drill.
We use all of the resources in addition to our iPad, but the apps I've found most helpful for geography are
Montessori Approach to Geography (each continent)
Stack the states
Stack the countries
Shake the states
Spell the states