Another update: Gas Cubby 2.7 was submitted and is awaiting review and approval from Apple. Hopefully it will be out soon and everyone can have their beloved Gas Cubby working normal again. Thanks for your patience as we make our way through this iOS transition.
To elaborate, the app now crashes whenever I try to look at any existing information, i.e. opening a recent fillup, trying to look up car info, etc.
Same here on my iPhone 5S running iOS 8 and Gas Cubby 2.6. I can upload a new fillup, but cannot go back and review any historical data without crashing the app. I sync with my iPad (4th gen) and the 2.6 version works just fine on the iPad. I do not want to carry my iPad in my truck all the time. Hopefully the bugs with the iPhone will be fixed shortly.
EDIT: For clarity, my iPad is running iOS 8 and Gas Cubby 2.6 as is the iPhone 5s.
I am having the same issues with my iPad Mini running iOS 7.1.2 and Gas Cubby 2.6 as others have mentioned using iPhones. Cannot change the date or time when entering. Have not had any crashes yet. The icon looks like a bulls eye, not the Gas Cubby icon. Hoping version 2.7 fixes this and Apple hurries to approve it