The My Little Pony Game has a short chapter on Klugetown that bridges the gap in the movie between the ponies leaving behind Celeano's crew, and the part where they all meet back up with Capper in tow. This was part of Update #30 released a few days ago.
Head on down below for the copy-pasted explanation, and video!
From Сергей:
They met each other again in Klugetown, realized they both want to help ponies to defeat Storm King and decided to team up for that. But before heading out, Capper needed to pay his debts to Verko and Celaeno helped him by sharing treasures she was hiding since the times she was a pirate. However Verko didn't want to let them go as they've been the reason for his recent problems and ordered to catch them.
Capper and parrots managed to hide away and decided to start an uprising since they weren't the only ones in the town who didn't like Verko. They turned all the citizens on their side, Verko was left alone and was overthrown, and they even made him learn a friendship lession that you need to earn the friendship and not to buy it.
