Apple is currently testing the Journal app with the company's iOS 17.2 update, but there is currently no indication that it's going to come to the iPad or Mac any time soon. In fact, there's no suggestion that it'll make its way to those platforms at all.
Apple announced the Journal app as part of the iOS 17 update back in June before saying that it would arrive later this year. There's still no official date for that, but those who are testing the iOS 17.2 update are already able to take the app for a spin - although few are raving about its current capabilities. However, as 9to5Mac notes, there is currently no sign of the Journal app in the macOS 14.2 or iPadOS 17.2 betas. And Apple has so far been surprisingly quiet about the chances of the app coming to the Mac or the iPad at all.
Discussing the fact that there is no Journal app on those platforms, 9to5Mac notes that Apple's iOS 17 webpage is the only one that makes any mention of the mindfulness and journaling app - it can't be found anywhere on the macOS Sonoma or iPadOS 17 webpages.
The app itself has the potential to be a big one for users thanks to promises of its ability to recommend content that could make for a good journal entry. However, the lack of apps across other devices might still make the likes of Day One a better option for a ton of people. Especially if those apps can tie into a Journal API to surface the same suggestions.