Uplet is an Instagram app for MacBook Pro, as well as an Instagram app for Mac desktop and all kinds of Mac machines. The software allows you to upload multiple pictures at a time directly from Mac – you thus save yourself a lot of time and effort while retaining the original quality and resolution of your pictures.
The developer is known to keep up with the latest updates on Instagram, so it is likely that in the near future direct messaging feature will be integrated in the app, and you can send messages directly from Uplet.