I estimated a savings of $ 15 — $ 20 per day, but it could easily be more if you did the exact same activities on your own. (moneysense.ca)
Just because your twins spend a lot of time together, it doesn't mean that they both have to do the exact same activities during playtime. (pregnancy-info.net)
It also includes a similar easy to use app and tracks the exact same activities. (digitaltrends.com)