Instamate is not working anymore, and seems to have shut down.
Here is a Instamate alternative for posting to Instagram from a PC.
Schedule Instagram posts from a computer
A simple Instamate alternative is OneUp. It is web-based, so you don’t have to download a program onto your computer, nor do you have to have OneUp running for it to post.
With OneUp, you connect your Instagram account from a desktop computer, then click “Schedule Post”, which takes you to this screen:
In OneUp, you select which Instagram account(s) you want to post to. You can choose one Instagram account, or you can post the same photo to multiple Instagram accounts at the same time. You then upload your photo, write your description with any hashtags you want to add, and choose to either post it now, or schedule it for a future date and time.
You can even choose to have the Instagram post automatically repeat at set intervals if you want:
Here is what the post looks like on Instagram:
OneUp allows you to easily post on Instagram from a desktop computer, and to schedule out posts weeks and months into the future.
Another great thing is that OneUp schedules the post, then directly publishes to Instagram with no push notification needed. You can add hashtags and @tag other users in the post description too.
OneUp is not free, but starting at less than $5/month, OneUp is an affordable Instamate alternative for posting to Instagram.
OneUp supports scheduled posts on Instagram, Facebook, Twitter, Pinterest, LinkedIn, and Google My Business.
Unfortunately, OneUp does not support video posts or multi-image/carousel posts to Instagram at this time.