Ive used this App for years. It does all I need it to do. Backup, Restore, at least 4 formats including a nice HTML export option, includes Notes (most dont.
I did notice that the file sizes grew astronomically when using on my iPhone 6 versus my iPhone 5 - by like 40x larger. Not sure about why that happened (iOS or Contact Tools).
Im pretty sure those iPhone 5 backups had nearly as many contacts and data, but something happened to cause the file size to jump.
But being able to upload to Dropbox instead of emailing is seamless, so file size is not an issue for me.
I recently bought a 64GB HooToo. Its a thumb drive with a lightning connector. The iPlugmate software that works with it claims to backup contacts. Its worthless compared to Contact Tools. I wont even go into the details of its deficiencies.
Give Contact Tools a try. Ive looked far and wide and cant find anything close to this App.
CG03026 about Contacts Tool, v10.1.0