I don't know what's the best, but, on the desktop, among other things I tried, I used GnuCash.
In addition to tracking personal/business finances in GnuCash, I used the invoicing feature to track billable hours and notes for each chunk of time. I had a custom invoice format that generated PDFs without the notes, and then I used the notes as reminders of what to put in periodic work reports.
A drawback to GnuCash, though, is that you can spend a lot of time getting your accounts and transaction splits just right, and tracking every little transaction. One of the best things I did was to move to doing less categorization and itemization in GnuCash (e.g., unless an expense was was tax-relevant, it got moved to "Misc.", and paper-money expenses weren't even tracked, but reconciled monthly).
In addition to tracking personal/business finances in GnuCash, I used the invoicing feature to track billable hours and notes for each chunk of time. I had a custom invoice format that generated PDFs without the notes, and then I used the notes as reminders of what to put in periodic work reports.
A drawback to GnuCash, though, is that you can spend a lot of time getting your accounts and transaction splits just right, and tracking every little transaction. One of the best things I did was to move to doing less categorization and itemization in GnuCash (e.g., unless an expense was was tax-relevant, it got moved to "Misc.", and paper-money expenses weren't even tracked, but reconciled monthly).