Toca Boca Days is no longer downloadable for new players as of August 20th, but if you're an existing players who uninstalled the game but still want to access it before its planned shut down after August 25th, you can still access it through the following steps:
- Go to the App Store and tap on the account icon in the top right corner.
- Click Apps (If you have a Family Sharing then also choose "My apps")
- Scroll through the "Not on this iPhone/iPad" tab until you find the app(s) in question and tap the cloud icon on the right for the app(s) you want to download.
Keep in mind, even if it'll remain downloadable from your app library/purchase history, after August 25th all services will be made unavailable and by extension make the game inaccessible.