I've written about Soulver for my Mac–a notepad calculator that allows you to mix words and numbers. And now Soulver is available on the iPad. Soulver is my favorite app for budget and grant planning. I can jot down my ideas line-by-line. If I make a mistake, I erase a single line (rather than starting over). Because I can mix numbers, calculations, and words, I am able to reconstruct my thoughts days, months, or even years later. And since Soulver syncs through Dropbox, I can share my work between my Mac and my iPad. The iPad version is currently selling for $2.99.