If I purchased an app for my business on Itunes, paid by my personal Itunes Balance, how do I record this on the corporate ledger?

It depends on how the company is taxed

if you are a sole proprietor or a partnership, then post the purchase as being from owner/partner equity investment. Number of ways to do that, but easiest IMO is a journal entry, debit expense and credit equity investment

if you are taxed as a c- or s-corporation, then you create a liability account named something like due to [name] and use a journal entry, debit expense and credit liability. later the company pays you back using the liability account as the expense (reason) for the payment