Table 2. Taxonomy of the topics.
| Category | Topics | Topic rate | Total rate |
|---|---|---|---|
| Development | Arrays | 4.42 | 36.14 |
| Error handling | 3.93 | ||
| Authentication | 3.79 | ||
| Project building | 3.28 | ||
| Emulator | 2.98 | ||
| Casting | 2.81 | ||
| Event issues | 2.77 | ||
| App crash | 2.69 | ||
| Connection | 2.62 | ||
| Notifications | 2.10 | ||
| Functions | 1.83 | ||
| Threading | 1.79 | ||
| Testing | 1.13 | ||
| UI settings | View controller | 3.74 | 27.84 |
| Web view | 3.57 | ||
| List view | 3.07 | ||
| Button actions | 2.97 | ||
| Text settings | 2.92 | ||
| Layout settings | 2.80 | ||
| Style-theme | 2.78 | ||
| Fragment activity | 2.43 | ||
| Navigation bar | 2.31 | ||
| Dialog alerts | 1.24 | ||
| Tools | Android studio | 4.95 | 16.92 |
| Kotlin | 4.45 | ||
| Flutter | 3.34 | ||
| React-native | 2.80 | ||
| Xamarin | 1.39 | ||
| Data management | File settings | 2.48 | 8.13 |
| Database tasks | 2.16 | ||
| Firebase | 2.07 | ||
| Cloud firestore | 1.42 | ||
| Multimedia | Imaging | 3.45 | 5.51 |
| Media streaming | 2.06 | ||
| Mobile APIs | API requests | 3.34 | 5.46 |
| Map API | 2.12 |