Zotero has a user-friendly iOS app that works on both iPads and iPhones. You'll share items to the Zotero app. If you have a free Zotero account, the items then sync with your online Library and can be synced to your computer.
The basics of using a Chromebook with Zotero. You'll need the free online account to use the browser extension without the computer app (see next link). You can't install the desktop app on Chromebook unless you have a specific version and are comfortable experimenting with installation via terminal (see last link in this box).