Streak Rewards

[alythobani]

Gamify the app (user can opt in/out) so that as the user generates larger streaks, the user receives rewards in the form of freebie/cheat days, where they can choose to ignore a good/bad habit and have it count as successful still for that day.

Notes to remember for later when I code this up:

• maybe give 1 cheat day per 5 successful days
• don't let freebie days count towards rewards or that could lead to infinite cruising on them
• also give freebie day rewards for unlocking achievements, e.g. for getting a streak of 50
• maybe limit the number of freebie tokens a user can have at once so that we're not encouraging crazy binges actually, let them do what they want, they earned it