I use DiveLog DT and Dive Log for iOS with my MacBook and iPhone/iPad (from moremobilesoftware.) Put several links below so you could see screenshots of the different apps. There is also a free desktop version, DiveLog Manager, that works with iOS, and although it looks the same, I don't think you can do as much with it. The first link doesn't show all of the features of the app but lets you click on info for all of the apps. The desktop app may also be compatible with Windows.
Developer's website:
Dive Log Manager/DiveLogDT
App Store with info for DiveLog DT (desktop):
DiveLogDT
App Store with info for Dive Log (phone):
Dive Log
want to do it only so my dives follow me everywhere
I generally download data from my dive computer to my MacBook when I get home from a trip. DiveLog DT is compatible with Shearwater - not familiar with your specific dive computer, but for me, a download cable is necessary for the download - I know some dive computers download wirelessly. I add/change any info I want and then, through bluetooth, put it on my iPhone/iPad. You can also hand enter info on your iPhone and then, through bluetooth, have it on your desktop/laptop. You can also merge info from both devices.
My dive log being on all of my devices is one way it follows me everywhere. The other is that I can save my dive log to the cloud (obviously for me, iCloud) - as long as you keep an updated backup in the cloud, all of your dives can follow you anywhere.
Do you know if there is a mechanism for the dive buddy to sign off on the logs?
Dive Log on an iPhone/iPad allows for a signature for dive buddy/DM. More Mobile Software keeps the app updated and they are easy to contact if you have questions. Too many features to write about, but one of the latest features they added, that I like, is the addition of a photo library of marine life - I can add pictures that I took.