However does anyone know a good app which shows altitude and speed as well as position from the log?
Where is the log kept?
I have found that the iPad in general is a bit of a one-way street ending in a cul-de-sac: You can get (data) in, but you can't get (the data) out. This is because all the apps live in their own "sandbox" which is inaccessible to other apps. If the app doesn't supply a method to get the data out, then the only way of getting the data out is to jailbreak your iPad.
So if the log is kept in Air Nav Pro, and that app doesn't give you the altitude data you want, and also doesn't allow you to export the log, then you're pretty much stuck.
On the other hand, if the log is kept in the Bad Elf itself, and you can access the data over USB in some sort of standard format, then there are tons of sites where you can convert this to other formats (even XLS if necessary), and eventually import it in any navigation app. Google Earth or Google Maps might be an option, and if you want to look at each and every track point in detail, then OziExplorer would be my recommendation.