As we already got multiple voices on this, let me sum up an answer from the comments:
- We already had a related discussion here: Apple mobile device tags
- We have comparable tags, e.g. web-apps, google-apps
- We also have related tags without the
-apps suffix, e.g.: android, windows, linux
- Tags without the
-apps suffix are usually OS tags (as the examples show), while those having the suffix are not – but are rather specific to a vendor or technology
Conclusion: As in this case, the base name again is device specific (which is more close to "vendor specific"), the iphone-app is the one that should remain, and iphone should be merged with that target and then be made a synonym (to avoid it from being re-created as tag).
For the remaining part (this still leaves us with two iOS specific tags), see the already mentioned discussion in Apple mobile device tags – this is a completely different think and was not intended by me to be a topic here; I solely cared about the two iPhone tags in this context.