I couldn't find a check register app that calculated running balances in addition to current and ending account balances. My main concern is not knowing how much money I currently have, but how much I'll have on a specific day... IE, the day before I get paid.
I ended up writing my own. It's been about a month since I started learning Java & Android, but it's coming along nicely. I'm still building out features for the paid version, but the free version allows you to track multiple accounts, filter your transactions by hiding reconciled transactions, and gives you a running balance for each transaction.
edit: Some of these screenshots are dated, from the early point in my development. The latest version is a little cleaner looking.
Here's the QR for the free version for anyone that would like to check it out:
