This app was mentioned in 2 comments, with an average of 1.50 upvotes
I made a free app a while back as a side project that lets you search ICD10 codes by name or category. No ads or anything, and I am looking for feature suggestions. Android-only right now.
Hope it's useful to someone.
We were going to bring it to iOS, but apparently you can only develop for it with a Mac. The app is essentially just a tree view of the nested codes. So you see a list "A00-B99: Certain infectious and parasitic diseases", "C00-D49: Neoplasms". You click the first one, and its a description of A00-B99 with the related, excluded, etc. codes. Below the description is a new list for the subcodes, and that repeats going all the way down. Here's a google play link that you can view in a browser with screenshots.