Implemented timer into task details, uploaded example images for app and centred headers on all screens

lib/asyncStorage.ts

@@ -1,6 +1,13 @@
 import AsyncStorage from '@react-native-async-storage/async-storage';
 
 const notificationKey = (aId: string) => `assignment_notification_${aId}`;
+const activeSprintKey = 'active_sprint';
+
+export type ActiveSprint = {
+  taskId: string;
+  durationSeconds: number;
+  endTime: number;
+};
 
 export async function SaveAssignmentNotificationId(aId: string, notificationId: string) {
   await AsyncStorage.setItem(notificationKey(aId), notificationId);
@@ -12,4 +19,22 @@ export async function GetAssignmentNotificationId(aId: string) {
 
 export async function RemoveAssignmentNotificationId(aId: string) {
   await AsyncStorage.removeItem(notificationKey(aId));
-}
+}
+
+export async function SaveActiveSprint(activeSprint: ActiveSprint) {
+  await AsyncStorage.setItem(activeSprintKey, JSON.stringify(activeSprint));
+}
+
+export async function GetActiveSprint() {
+  const activeSprint = await AsyncStorage.getItem(activeSprintKey);
+
+  if (!activeSprint) {
+    return null;
+  }
+
+  return JSON.parse(activeSprint) as ActiveSprint;
+}
+
+export async function RemoveActiveSprint() {
+  await AsyncStorage.removeItem(activeSprintKey);
+}