It seems there’s no consistency in how developers define their bundle IDs. Even Apple application IDs1 are not consistent. This makes sense considering that once you define the ID, you can’t change it. So think carefully.
I would hope I can come up with a guideline. I think there are 4 possible scenarios.
- Display name “Podcasts”. Bundle ID
com.apple.podcasts
- Display name “TextEdit”. Bundle ID
com.apple.TextEdit
- Display name “Voice Memos”. Bundle ID
com.apple.VoiceMemos
- Display name “iMovie”. Bundle ID
com.apple.iMovie
We can come up with a single rule. Use lowercase, unless, your app has at least one capital letter in its name and it’s not the first letter.