If you try installing or updating an iOS app, you may receive a pop-up message that states the download is over 100 megabytes and may not complete downloading.
This item is over 100MB.
Unless an incremental download is available for this item, “” may not download until you connect to Wi-Fi.
You can now hit OK and the download will complete over cellular. It seems this can not be bypassed if you still choose to download and even if there is no incremental download available.