I bought the streak freeze one day but ended up using Duolingo that day. I have never missed a day, and had it equipped ever since. Is it only used on a day you do not use Duolingo?
Yes it is, however, you can keep it as long as you like. It never expires....I had mine for over 2 years back in May when I had to use it, and I've since bought another and have yet to use it.
yep and you can have it equipped forever if you never missed a day but as soon as you miss a day you have to equip it again so keep in mind you can't miss more than a day
A streak freeze is always equipped there if you buy it unless you miss a day and it will be used. you don't have to use it the day you buy it, you can just store it there just in case. I recommend buying one just in case.