I am looking for an Ipad App that my field technicians can use as an on site invoice or estimate processor. Which in detail allows them to give customers and estimate or invoice for work...

In addition, it is important to have the ability to link those invoices/estimates to our main system (no system in place)... We currently use a paper system linked to excel. Need recomendations

I cant find anything with good reviews...

Thanks for the help

It sounds like you could do this with a combination of a spreadsheet and online storage.

For the spreadsheets the three most popular are Numbers, Documents to Go, and QuickOffice. Numbers offers the easiest formatting tools on the iPad, Documents to Go is probably the most compatible with Excel, and some people prefer QuickOffice for how it works. (All opinions except Numbers are from hearsay and articles)

All of these will upload and download with the online storage solution DropBox. DropBox can also be set to keep folders synced on a computer. The result is that whenever someone saves a spreadsheet to DropBox from their iPad (and has an internet connection), a few minutes later it will also be on the computer(s) you've set up with DropBox.

Note: Numbers must use an additional service called DropDAV to use DropBox.

I'm pretty sure there are a couple of invoice and billing apps for the iPad, but don't remember what they were.

I have used invoice2go the free version