Photok - A safe place for your photos. It stores your photos encrypted on your device and hides them from others.

Free Texture Packer - Free Texture Packer is an open source tool that allows you to pack multiple images into one atlas for you games or sites.

Google Photos - All your photos are backed up safely, organized and labeled automatically, so you can find them fast, and share them how you like.

Sprite Monkey - Small and fast but still full-featured sprite sheet editor.

Hide Secrets - Hide Secrets is an app that allows hiding everything they deem confidential on their smartphone.

Sprite Sheet Packer - Sprite Sheet Packer is online that you can easily use to pack sprite sheets, including data formats for CSS, LESS, and Phaser.