To those who use some sort of spreadsheet on the phone, do you prefer spreadsheet (excel) or a different app with similar capabilities? I don't need to have access to ALL of my spreadsheets, but there are definitely some that would make my life easier if they were accessible while I'm on the go. There seem to be a lot of options, so I'm asking for advice from people that have experience using one that they love. Pros/cons. Thanks in advance!