I'm looking for a webservice or free utility to make time estimates for software development. My typical estimate consists of a series of tasks (each with a description, units, hours per unit) grouped (with subtotals in hours) + buffer option in percentage, resulting in a total hours + effective time (total hours spread over a schedule, for example 6 hours per day 3 days per week). Not sure if this breakdown is common.
Image explains more than a thousand words..
I do not need any billing functionality. Might make a good coding snack, or there might be something out there that's more tailed than Excel and save me time. Optional features: it could possibly collect all the estimates I've made in the past grouped by client and if they could be signed off via email then it would be completely perfect.