I like that it can be used with other software such as Dropbox to verify documents, also you don't have to use an email address which is nice because sometimes my emails go missing or are hard to find when doing so! Sometimes there's issues like this where notifications don't automatically show up in the app after sending something for example. Also sometimes if a document needs uploading before viewing then it doesn't always work properly but overall it functions fine though nothing too major has been noticed yet. I would recommend using blocknotary instead of signing things through other services such as dropbox, google drive etc since signatures via those online platforms could potentially get stolen by hackers. Signing documents makes them more secure than just leaving everything open to the public.