That sounds like the same mission of every other photo-sharing service, but Mustbin 3.0 brings a few interesting ideas to the table. The app automatically starts in camera mode (after you register for a free account), and everything you shoot is backed up to Mustbin's cloud. The photos never hit your iPhone's camera roll; instead, they're encrypted end-to-end in Mustbin with the AES-256 standard.

Once you've shot some photos, you can share them by tapping on the camera roll icon in the top-right area of the screen. Any photos you shoot in a single session will be pre-selected to make it easier to share them, but you can pick and choose anything else you might want to send. The default sharing option is through Mustbin's own secure chat features; with messaging and photos being two of the most important features for smartphone users, the company decided to marry them together in its app.

What's nice about Mustbin's sharing and messaging features is that it's built with the notion of sharing multiple pictures with multiple groups of people in mind. You can quickly shoot photos in the Mustbin app, hit the camera roll to have them all selected, and then share them with multiple groups of contacts in one seamless process. Sending photos is table stakes for any messaging app, but Mustbin makes sharing the same set of photos will multiple contacts or groups faster than most other options out there. You can also create shared folders that multiple participants can upload images to, if you'd rather move image sharing out of your conversations.

One primary use case Mustbin is pushing is for when you want to keep certain photos private and secure. The company noted that not everyone is comfortable sharing photos of their kids on Facebook or Instagram, for example (despite what I see when scrolling through my social networks). Mustbin wants to be a sort of private network for those kinds of images, where you share them with only your most trusted contacts. It works best when you're sharing with others Mustbin users, but you can also easily export photos and other files from the app using the default iOS sharing controls. Of course, you lose the benefits of the company's security credentials if you do so.

The company has put a number of factors in place so that your data stays private. When you create a Mustbin account, your phone is given a key to decrypt files on your device, but Mustbin doesn't have access to that key. The company can't see anything else you upload to its servers and couldn't unlock it even if it wanted to. The app itself is also protected with a pincode and Touch ID; once you unlock your account with those security measures, your key is unlocked and the files are decrypted. And there's even a "take back" feature which deletes any photo you share from the recipients' Mustbin account. Yes, your contact could have saved that picture to their phone's local storage, but it can be useful as a quick undo if you send the wrong image to the wrong person.

Mustbin still retains its legacy as an app for storing whatever you want beyond photos. After creating a "Bin" (what the company calls folders), you can add photos and text notes or create backups of credit cards and important passwords using a variety of custom forms; it's all encrypted and stored in Mustbin's cloud. The company isn't offering unlimited storage right now — you get 8GB free off the top, and the company says it'll reevaluate how much storage it offers depending on how popular its new photo features get. A Mustbin rep assured me that if users start hitting that 8GB cap, they'll find ways to expand storage to keep people using the app.

That's the main goal for Mustbin right now: retaining users and adding new features. In that sense, focusing on photos and messaging makes a lot of sense. They're probably the most important things we do with our smartphones, and users are already sending eight times more messages over the last six months than in six months before that. Now that its users are used to sending messages, the company hopes to see a similar increase in photo sharing by putting the camera front and center. Easier said than done with the many photo-sharing options on the market, but with security increasingly becoming a selling point for many companies, Mustbin may be a good option for the right audience.