If you use Instagram, chances are you've already started to see your friends posting collages of their "top nine" photos of the year. The first year I started noticing these I spent a solid half hour at least trying to figure out where to find the collage within Instagram's app. Spoiler: you're not going to find it in there. It has the look and feel of a built-in Instagram feature, but it's not.
The collages are created by third parties. You've got a few options if you want one, but the "best" of the bunch is likely topnine.co. With it, you enter your Instagram username (or anyone else's you'd like) and your email address. After a few minutes, a JPEG collage of your top nine pics of the year, as well as a rundown of how many likes you received throughout the year will show up in your inbox.
This pic is from doing it on my desktop:
The topnine.co website is done by the same folks who run the "Top Nine" app, which you can also use to get the same results.
I'm not personally stoked about the idea of handing over my email address for this one, but the site claims you can revoke consent to receive emails anytime by going to topnine.co/forget-me.
If you'd like to create a collage without handing over an email, you can do that at the 2018 best nine site. That one doesn't require an email address, but it does place a gnarly watermark on your collage, which isn't ideal if you want to share it with the masses. It also takes significantly longer to get your actual collage. The first few times I tried it took so long I was convinced it was broken.
And this one might be obvious: But since these are just scraping your account, not requiring you to log in, both of these require your profile to be public in order to work.