Yes totally, i did the following with my old iphone and it worked out fantastic
1. Appstore - downloaded amazon
2. Seached amazon for a pcm hd recorder and also obe with good dual microphones and hd capable video
3. Bought said device
4 proceeded to use a specific tool best suited to said specific task
There are good options out there, sony, zoom and olympus work well.
I ended up going w olympus ls20m,
It is discontinued for usa but can bought new from japan i think still runs around 300 to 400 butnusa canfound for sub 200 used at pawn shop every once in a while, otherwise retail is mid 200s or so dollars it does also allow external mics so you can do different placeents for audio and video sensing, i. Looking to expand mine's capabilities with the 30 m mics it is compatible with, as i already upgraded to the wireless remote and receiver which allows for easier solo operations and easier recording of my piano lessons
These are the onboard highly sensitive mics
And here are compatible add ons for even better fine tuning
Other options
Ie sony.hdrmv1
Or zoom q8
Audio only good ls100m
Also consider tascam but for video cimbined w sound oly has been fantastic for me and you cannot go wrong w other current options
All in all the process took a few mines of searching, add to cart and payment. I bought a factory refurb saving even more and so glad i tried to stop usng a phone to record.
My plan b would have been external microphone interfaced w phone but those are good for audio only i think, i do not recall being able to confirm being able to use phone for video while routing audio to the microphone
Topic: Recording suggestions for iPhone