hello, bro! Hoping you are fine. please check the below answers:
1. If your IP phone version is V200R003C30, you can't install any APP in the IP phone. it does not support in this version.
2. If your IP phone version is V200R003C00, you can download the app through the browser, but we don't suggest you to do this, because if you install too much APPs in the IP phone, it will effect the IP phone performance.
Hoping this can help you.