Mobile App Authentication and Registration Screen Design
Authentication screens are rejected from App Store more often than seems necessary—not for functionality, but for non-compliance with guidelines. Sign in with Apple is mandatory if the application has any other third-party account login method (Google, Facebook). If an application offers "Sign in with Google" without an Apple ID button—this is rejection per guideline 4.8. Design must account for this from the start.
What We Design
Login screen—email/phone + password, social login buttons (order matters: Apple first on iOS), "Forgot password" link, registration link. Inline validation—not popup, but hint below the field. Button loading state during request submission (not just disabled, but spinner inside the button).
Registration screen—minimal field set: do not collect what is not needed right now. If only email + password is needed—only that. Birth date, phone, profile photo—can be requested later, in the profile.
Forgot Password—separate screen with one field. Confirmation screen after submission. Instructions should explain what to do if the email did not arrive (check spam, retry timer).
Biometric auth—Face ID / Touch ID badge on login button if biometrics is enabled. On Android—BiometricPrompt system dialog, which is not styled.
For each screen—states: empty, partially filled, error (wrong password, email taken, no network), loading, success.
Technical Details Affecting Design
Keyboard covers form fields. On iOS UIScrollView with contentInsetAdjustmentBehavior solves this in code, but the designer should project the behavior: does the form scroll under the keyboard or does the screen shift up? This affects the positioning of the Submit button—it should not be "under" the keyboard.
Password field—secureTextEntry. Show/hide password icon—standard. Place it on the right inside the field.
Autofill—textContentType on iOS (.emailAddress, .password, .newPassword) and autofill hints on Android. Design should account for the possibility that the field will autofill—the floating label rises.
Timeline
Complete set of authentication/registration screens (login, register, forgot password, success states, error states)—1 business day.