|LeapFrog Download Card|
My younger son has a LeapPad 2 which is very much his device (he does lend it to his big brother sometimes.)
He spends a fair amount of time using the apps that came included with the learning tablet, but I do occasionally by him some new content.
I usually prefer to download the content rather than getting a cartridge because then we don't have to remember to take the cartridges with us, and there's more content available to download including smaller items.
The content for the LeapPad and LeapSter can look a bit pricey compared to apps for a tablet. But we do find that it is good quality and you know it's going to be age appropriate and adapt to the child.
One way of getting the cost down is to buy a physical download card at a price below its face value. The price of the $20 LeapFrog giftcards on Amazon varies daily but you can often get a good discount this way. You do need to take shipping into account so it's best to do this when you have something else you can order to get free shipping.
At time of writing, there's a good deal for UK LeapPad and LeapSter owners: LeapFrog Explorer App Center Download Card (UK)
The other thing you can do is sign up to the LeapFrog email newsletter which includes details of discounts. I happened to manage to get a 20% discount on one of my recent purchases this way. This makes a big difference!
We do like our tech. But we like it even better when we can save money!