Good job shipping! This was the kind of app I first worked on as well, but I never ended up putting it on the store, and kind of lost interest halfway through porting it to iOS 7 :)
The Add Transaction screen was pretty much where I lived in my app (http://imgur.com/DobW80r), so good work keeping it simple and efficient!
Some feedback:
* Might be worth making the user's current currency (you can get it from NSLocale) the default currency so that out of the box on first use they can start entering data, it's not great to have to go to settings first time you use it.
* If you must stick with hamburger menu, consider making the view tappable everywhere and not just on the hamburger icon, to dismiss it. Though I would argue it's worth using something like UITabBar to switch between log and charts if charts is something you use a lot.
* When tapping on a transaction to bring up the context buttons, consider allowing tapping anywhere on the screen to dismiss it, not just on cells.
* Consider a custom input view for the amount field, here's an example of what I did for my app (http://imgur.com/yp27cxK), gets rid of the ugly "dialer" style ABC/DEF/GHI annotations. More maintenance though.
* Understand its for you mainly, but tag editing would be nice :)
* When you have a couple of thousand transactions in there (I had 20,000), being able to quickly whip up some adhoc queries for interesting stats becomes a lot easier if you have an SQL backed data model, and I used SQLite+transactions just because I was paranoid of some stupid bug corrupting all the data. Knowing myself, I would delete an app the first time it lost any data.
However, long term, I think the solution for this kind of app is direct integration with banks (one of the reasons I lost interest, because I started getting super tired of typing in the data on a phone)!
Best of luck, and keep on iterating! Never forget what the first version of popular slick apps looked like, a lot of them were pretty basic.