Dear sir:
We developed that kind of app for scheduling, job evolution/tracking, graphical/lineal data viewing, estimations/deviations (time, costs valuating), ... for Desktop environment but we will have not problem to develop it in web environment.
If you send us a funcionailty/requirements detail we can estimate time for developing.
You will no have to pay us project price amount until project will be finished and running ok.
Initial 20% YES, We trust in nobody.
Carlos Lopez
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