This app is free. There is a paid version (0.99 USD).Why is it the simplest one? Its is one page, including expenses, incomes and budget. You can see everything on the page. If you want excel files or notebooks for your expenses tracking, I think this app is the right for you. Just try this version for free. Then, if you like it, please download the paid version before its is too late. Why? Because all the data maybe lost and you must enter all the last balance again.This app does not connect to SMS or bank accounts or credit cards, or even your contact list. It does not have password protection or login. I have written this app because I need something simple like excel files and notebooks but more handy, and it has to do all the calculation for me. And after finishing the app, I like it so much that I want to share with all of you, who have the same interest like me.Please enjoy it like enjoying every moment of life. Thank you for reading and using the app.