Starting with version 5.0.4 all your monthly packs can be easily found in one place - in a new category 365 days!
The packs are displayed as a timeline. Just scroll the timeline to the pack you need to find.
Now in a monthly pack you can see two pictures for each day: one is a regular free picture and another one is extra. You can open an extra picture using 100 coins, asking a friend for help or open all extra pictures in a pack by purchasing them. An extra picture can be opened only after a free picture of the day is solved.
In order to access a puzzle you finished before just click on it: