If you’re sharing to WhatsApp… just use their editor, it allows adding stickers and emojis natively, it doesn’t auto detect faces… but is that strictly necessary?
For double points, if you don’t wanna share on WhatsApp you can still use their editor and just send it to yourself. Now you are still only using one app, and the new photo is saved automatically to your camera roll.
…but this is actually not easy to do via the iOS markup editor. It defaults to a pencil tool that draws way too fine of a line to mask a face without a loooot of scribbling, and adding a shape is a lot of taps. And text, forget about it, that's a pain in the default iOS editor. (Instagram: way better at this.)
This is a weird niche of a tool—it's for people who are posting photos to the Instagram timeline where you can't use the built-in stickers feature, or sending a lot of photos via Messages. But for this tiny niche: sure, useful.
Just tested it out and I was easily able to put an emoji over a face and resize/rotate it with pinch/drag type motions. Anything like that in the default Apple app?
Granted, there is nothing like the automation features in OP's app, so at least that part is interesting.
If you insert a photo into Messages and hit Markup, the first view gives you a bunch of pen/pencil/brush options, with fixed sizes per brush. There's a plus button that allows you to insert shapes and text…but you can't pinch-zoom to scale the text. You then have to tap around again to set the font size and color.
It's a weird, neglected-feeling interface. They could borrow a lot from Instagram's story editor.
I don't use social media, but I have a group chat with a handful of close friends. Sometimes, I like to insert emojis into a photo for comedic effect.
Now I can do this without fighting with iOS's horrible Markup editor.
(Quite frankly, I'm surprised that this isn't part of iOS already.)