Review on Add-On Data by Deshaun Fisher

The most useful thing for me is that you can get it anywhere, so if my client doesn't have access I just log in with their credentials using a VPN or something like that.

It has limited support for custom fields (or at least no easy way). You will be spending time training people how to use this tool effectively because there's not many ways around creating forms manually which takes more work than doing them through an add-on data solution. This could make your life easier as well as save you money by having fewer errors/duplicates entering into systems later down the road.