LOL Well... 'cept the sales for an iPhone app are usually much higher than for the corresponding Android app. :-) So if you're going to choose one... And the development environment for iPad is pretty nice. My dear hubby has about 60 apps out for the iPhone and iPad. No jumping through hoops. Build 'em, submit 'em (and wait...), support 'em.
I'm looking at the store now, and I don't see the "All" version yet. Maybe it's been submitted, but isn't launched yet?
The others are each $4.99, except Aikido-Intermediate 1, which is FREE, so you can see if you like them.
I'm glad your husband was able to get those apps out painlessly. It took my friend hundreds of dollars and months of hoop jumping just for the licenses. Android was under $100 and less than a week.
And popularity doesn't determine how good something is. Otherwise we'd all be doing a differen marital art.
I'm just razzing you. I do hope an Android version gets marketed sometime though.