There is a known issue with iOS devices that utilize 3D Touch, including the iPhone 6S and iPhone 6S Plus. When selecting an image thumbnail from your device’s photo library (e.g. camera roll), Palringo will crash if 3D Touch is activated by pressing too firmly on the thumbnail.
This is a iOS-level issue currently impacting all apps on iPhone 6S and 6S Plus that use the system’s default photo picker. It exists in all iOS 9 versions, up through 9.1 beta 5. Note that some apps with custom photo pickers (e.g. Facebook) may not experience the issue.
Apple is aware of and currently investigating a fix for this issue. In the interim, there are two workarounds:
When uploading images to Palringo from your 6S/6S Plus device’s photo library, tap the thumbnails gently and quickly
Disable 3D Touch (iOS Settings > General > Accessibility > 3D Touch > 3D Touch: Off)