I believe this already exists, unless I am not understanding the request. If your techs have access to mobile followups, they will be able to see all the estimates they have left, modify those estimates, or even add a new estimate to the opportunity. The only time we have run into trouble is where the technician didnt leave an initial estimate on the job so there is no estimate to "follow up on". I have always advised my techs to leave a Misc Estimate for $1 if they arent sure, just so it is there for them to followup and modify should they need more information to build out a complete estimate. Hope that helps!
Element Mist
