Score habit strength based on exponential smoothing algorithm

Show habit strength score based on exponential smoothing algorithm which is much suitable for showing habit strength than linear consistency or streaks.

The exponential smoothing curve much closely models to curve of habit strengthening and prioritises recency while still retaining a memory of past performance, unlike linear consistency curve. Linear consistency curve dilutes recent performance with past performance, and not even close to nature habit strength curve.

Streaks are a great motivator when they work, but more often than not they demotivates the user when their streak breaks which is common when building a new habit.