After I brought this news a few days, Grab Philippines announced that Grabjeep is now available for free.
For sure, that offer will be available for a limited offer only. Based on their recent FB page post, they will have some stops in Magallanes, Ayala, Buendia, Guadalupe, Boni, Shaw, Megamall, Ortigas, Santolan, Araneta and SM North EDSA.
There's no need to book via the Grab app. All you need is to grab the attention of the vehicle in their designated stopovers.
This air-con jeep also has WiFi. I'm curious on it's pricing soon as almost has the same route as most of EDSA-based aircon buses.