After all these years, and growing up with Windows 3.1, I have seen an entire evolution of computers and software. Touch screens and large resolutions were a pipe dream just 15 years ago. Now it's the norm. Going from a Packard Bell (yes, before HP) that couldn't run 3D Ultra Mini...
On the iPad version, you don't actually have to pull back as far as you think (otherwise your thumb goes off the edge).
Use the catapult unless you're a masochist.
Upgrade your reload time unless you're a masochist.