Smartphones are becoming larger, mainly because bigger screens offer a better experience for viewing content. One drawback of larger screens is that they make single-hand interactions difficult because of hard to reach touch targets and of the need to re-grip the device, both factors significantly reducing their usability. Flexible smartphones offer an opportunity for addressing the issue. We first set out to determine the use of common single-hand mobile interactions through an online survey. Then, we designed and evaluated one-handed deformable gestures that offer the potential for addressing the finger reach limitation on large smartphones. We identified that the top right up bend and the center squeeze up gestures are the fastest and preferred gestures. We found no hand preference, which indicated that the gestures could be implemented to fit the needs of a wider range of the population, instead of favoring right-handed users. Finally, we discuss the impact on deformable gestures on one-handed interactions issues.