App Components and Human Interface Guidelines

Develop UI for Android

Android Components

Design for Android

Official Android Design Guidelines

Android App UI Components

Use touch gestures

iOS Human Interface Guidelines

More specifically about UX in iOS

iOS In-app Terminology

Toggle Button

Snackbar with Action

Top App Bar

Floating Action Button and Extended Floating Action Button

Android Buttons: with text and no text (Image Buttons)

Bottom Sheet

Search Dialog vs Search Widget - Overview

Toast

Device System Bar, Device Navigation Bar - Android System UI Overview

Components not covered by collages:

Checkboxes

Radio Buttons

Spinners

Pickers

Navigation Bars

Action Sheets

Buttons

iOS App UI Components

Standard iOS Gestures